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INTRODUCTION DISTRIBUTED CONTROL SYSTEM: A CONTROL SYSTEM WHICH IS FUNCTIONALLY AS WELL AS PHYSICALLY DISTRIBUTED IS CALLED A DCS. DCS SYSTEMS ARE SUPERIOR IN COMMUNICATION REDUNDANCY AND DATA SECURITY AND AVAILABILITY OF ALGORITHMS DISTINGUISHES THE DCS FROM PLC. ADVANTAGES OF DCS OVER MICROPRPCESSOR BASED SYSTEM: 1. SYSTEM OVERLOADING IS AVOIDED 2. DOES NOT AFFECT THE WHOLE SYSTEM SYSTEM/PROCESS IN CASE OF FAILURES 3. REDUNDANCY (BACK UP )AVAILABLE FEATURES OF DCS: 1. PROCESS MONITORING MUCH EASY 2. PROCESS CONTROL AND OPERATION 3. SYSTEM CONFIGURATION AND ENGINEERING FUNCTIONS 4. ALARM DISPLAYS AND SELF DIAGONSTIC DISPLAYS (EASE OF MAINTENANCE). 5.SYSTEM DATA STORAGE, HISTORICAL DATA STORAGE, SPECIAL EVENTS STORAGE 6. FUTURE EXPANSION SIMPLE 7. I/O MONITORING, SEQUENCIAL AND LOGIC CONTROL 8. COMMUNICATION BETWEEN ALL MODULES FAST AND ERROR FREE DATA FLOW 9.GATE WAYS TO VARIOUS PLCS, COMPUTERS SPECIAL PURPOSE CONTROLLORES OTHER SYSTEMS ETC. BENEFITS OF DCS OVER CONVENTOINAL C & I EQUIPMENT : 1. REDUCTION IN CABLING IN CONTROL ROOM. 2. PHYSICALLY AND FUNCTIONALLY SEPERATED MODULES. 3. MORE UNIFORM OPERATIONS AND TIGHTER CONTROLS. 4. EXCELLENT INFORMATION MANAGEMENT. 5. CONSIDERABLE REDUCTION OVER MAINTENANCE EFFORTS (THROUGH BULT-IN DIAGNOSTICS).

1

CHAPTER-2 SYSTEM ARCHITECTURE

* Requirements for process control & Process Network * For continuous/discrete control strategy * Supervisory Network * For Human machine interface *Plant Information Network *For Management Information systems. 3.1 TDC 3000 LOCAL CONTROL NETWORK (LCN): The Local Control Network is backbone of most TDC 3000 systems. Its role is to link today’s operator stations processing modules, and gateways. Either of the two redundant cables can be designed as the active one the other is then backup. If the active cable fails or has an excessive error rate, the roles of the cables are automatically switched. The cables can also be switched manually from a universal station. Features of LCN: LCN uses Honeywell proprietary protocol. Structure similar to IEEE 802.4 Physical token bus, logically token ring. Deterministic Network using an operating system RNOS. Operating at 5 MBPS. Maximum 64 nodes contain one LCN. Maximum length 300mtrs. Stretchable to 4.9 km’s 20 Gateways can be floated on one LCN. Talks with DH through HG. Redundancy with AUTO SWAP.

2

FIGURE 3.1

3

FIG:3.2,3.3

4

3.2 LCN Nodes: 1. Universal Station: The universal station is one of the primary human / machine interface. This work station provides a single window to the entire system at the LCN level and below whether the data is resident in one of the LCN nodes or in one of the process connected devices. The US can be used to accomplish different tasks; it can be used by an operator, a process engineer, and by a maintenance technician to accomplish each of their different tasks. 2. History Module: The History Module (HM) which is available with different storage capacities makes possible storage of data and quick access to large quantities of LCN data such as A. History of process alarms, operator changes, operator messages, LCN system status changes, LCN system errors and LCN system maintenance recommendations and also continuous process history to support trends. B. System files of all types and other data required anytime LCN modules are reloaded or operating programs are changed. C. Process control data bases (called checkpoints) for maintaining up-to-date controller settings in the event a controller is taken out of service. D. On-process LCN maintenance information and analysis. 3. NETWORK INTERFACE MODULE (NIM): The Network interface module (NIM) is a node on the LCN that interconnects the UCN with the LCN. It converts the transmission technique and protocol of the LCN to the transmission technique and protocol of the UCN. A NIM almost has a redundant partner. Local Control network specifications Physical Characteristics: 1) Maximum length: 300mtrs (1000ft) for coaxial cable bus segment 2km (8562’) for fiber optic cable run. 2) Maximum number Of TDC 3000 Modules per LCN: 64 modules total for entire network 3) Fiber optic extension: Up to two fiber optic segments between two modules. Up to six fiber optic extensions connected to any Coaxial segment.

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Operating Characteristics: 1) Data Transfer speed

:

2) Data Encoding /Transfer method: 3) Real time clock signal

:

5 million bits per second. Manchester data encoding with token passing access protocol. Transfer over coaxial cable at 12.5 khz. Clock signal propagation between LCN extension is optional.

LCN NODE ADDRESS JUMPERS (DUAL NODE) LOCATED ON THE K 4 LCN BOARD: Ex: NODE NUMBER IS 43 Jumper out = 1 Jumper in = 0 The overall jumper removed including party Jumper must be odd number. Note that address 0-127 can be set but software allows only node address 1-64 If it is a 3rd generation k4 board dip switches are used instead of jumper here settings dip switch to zero or close sets the address. Each of the hardware modules (nodes) attached to the LCN here some common functionality consisting of an LCN interface mechanism a processor and memory. This common functionality is often referred to as the “KERNAL”. Processor – High performance kernel HPk2 – 2 mw memory board – E Mem – 1mw interface board – LCNI. PERSONALITIES: 1) Every node in TDC system specific personality software associated with it. 2) personality files are stored in HM. 3) when any node is loaded the corresponding personality software gets downloaded in the RAM of that node.. 4) Personality software defines functionality of a node. 5)

Typical US personalities are 1) operator 2) Engineer 3) Universal

6

LCN MODULES ADDRESS SETTING

FIG 3.4

7

LCN NODE MINIMUM MEMORY REQUIREMENT LCN NODE TYPE

SOFTWARE RELEASE 520

1) Application module (AM (Redundant or non- redundant) 2) Computer Gateway (CG 3) History Module (HM) 4) Network interface module (NIM) 5) PLC Gateway (PLCG) 6) Universal station (US) 7) US with universal personality

3 mw 2 mw 3mw 2 mw 2 mw 6 mw 8 mw

CONTROLLER BOARDS: The controller boards are unique to the node type. It is inserted in slot 2 of a DNCF. The LCN node can be identified from the controller boards it has NODE TYPE 1) Universal station 2) Network interface module (NIM)

CONTROLLER BOARD Enhanced peripheral display Generator (EPDG) Enhanced process network interface (EPNI)

PADDLE BOARD EPDG I/O NIM MODEM

3) Application Module (AM)

NIL

NIL

4) History module (HM)

Smart peripheral Controller (SPC)

SPC I/O

5) Plant network Module (PLNM)

Computer network interface

CNI I/O

6) Enhanced PLC gateway Enhance PLC interface (EPLCG)

EPLC I/O

7) Computer gateway

CLI I/O

8) Network gateway

Computer interface Network gateway interface

8

NGI I/O

3.3 UNIVERSIAL CONTROL NETWORK (UCN): The universal control network is one of two types of networks whose role is to link process connected devices with each other and with the LCN. The “PROCESS MANAGER’,‘ADVANCED PROCESS MANAGER’,’HIGH PERFORMANCE PROCESS MANAGER’ AND ‘LOGIC MANAGER’. Honeywell’s most powerful data acquisition and control devices. The LCN connection is through the network interface module, based on communication standards defined by the international standards organization the UCN operates at the same data rates as the LCN 5 megabytes per second peer-topeer communications between pm’s, APM’S HPM’S and LM’S on the same UCN is supported. FEATURES: 1) 2) 3) 4) 5) 6) 7) 8)

High-speed process control network. Built in security essential for safe operation. 5 Megabits per second, carrier band with token bus access control. Uses ISO open system inter connection standard with Honeywell extensions for process security. Real time redundant communication backbone for process connected devices. Supports Nodes such as APM, HPM, SM and LM. Supports deterministic peer-to-peer communications. The UCN uses redundant cables as standard, and can accommodate up to 32 redundant devices.

UCN NODES: ADVANCED PROCESS MANAGER: 1)

Performing data acquisition and control functions including regulatory, logic and sequential control functions, as well as peer-to-peer communications with other universal control network – resident devices.

2)

Providing bi-directional communications to Modbus compatible subsystems through a serial interface.

3)

Fully communicating with operators and engineers at universal stations. Procedures and displays are identical or similar to those used with other TPS controllers, as well as to APM and PM point displays.

4)

Supporting higher level control strategies available on the local control network through the application module and host computer.

5)

Using the same I/O and wiring as the PM, thus providing cost effective upward migration for the existing PM users.

9

and

Allen-Bradley

FIG 3.5,3.6

10

APM HARDWARE CONFIGURATION: The APM hardware can be divided into two parts, 1) APMM – Advanced Process Manager Module. 2) I/O Subsystem – Input Output Processors APMM: The APMM is responsible for - C0mmunication with the UCN - Continuous Control - Logic Control - Sequential Control - Peer-to-peer communication It consists of MODEM Transmitting and receiving data from UCN Advanced Communication Puts data in UCN format Communication between I/O link interface and control. Advanced I/O Link Interface Communicates with the IOPS Advanced Control Control function – regulatory, logic, sequence. A 5th blank card is part of the APMM board set. The power to the remaining “4” cards is routed through this card. i.e., the micro power switches under the top extractors of all these 5 cards are in series connection. In a redundant configuration all 5 cards are redundant. Failure of any one card results in change over of the entire APMM. One APM can support 40 redundant non-redundant IOPS.

11

FIG 3.7

12

I/O SUBSYSTEM: The IOPS are responsible for - interfacing to field equipment ex. Transmitters, I/P converters, Switches, relays etc. - Characterizing inputs and outputs. - Range and alarm limit checking for input points. The type of IOP depends on the signal from the field SlNo IOP TYPES

Signal

No of channels

1)

HLAI

4-20MA

16

2)

LLAI

mv, RTD

16

3)

LLMUX

mv, RTD T/C

32

4)

STIM

communication

16

5)

Pulse input

1-5v max fre 20khz

6)

AO

4-20MA

8

7)

DI

24v dc & 110vac

32

8)

DISOE

24v dc &110vac

32

9)

DO

24v dc & 110v ac

16

10)

SDI

RS 485, RS 422

2

11)

SI

RS 485,. RS422

2

8

NOTE: Redundancy is provided for HLAI, STIM and AO. Each IOP is connected to its corresponding FTA (Field Terminal Assembly). The field signals are terminated on the FTA. The FTA contains the signal conditioning circuitry

13

SOFT POINTS: The soft points reside in APM memory and there is no electrical wiring involved with this type of points. The various types of soft points are: 1) Logic Point: It is used for logic condition by using gates and comparators. 2) Digital Composite Point: Used as controller between digital Input and Digital Output with interlock and permissive features. 3) Numeric Point: Used for setting Numeric limits. 4) Flag point: Used for status of internal calculations. 5) Timer Point: Used for setting timer ON/OFF control. 6) Regulatory PV Point: Regulatory PV points provide an easy to use configurable approach for implementing PV calculations and compensation functions. The following selectable algorithms. Data Acquisition (Data ACQ) Flow compensation (Flow comp) Middle of 3 selector (Mid of) High low average selector (High Lo Avg) Summer Totalizer Calculator 7) Regulatory Control Points: Regulator control (Reg Ctrl) points are used to perform standard closed loop control functions by executing the algorithm that have been configure the following control algorithms are available . PID PID with feed forward PID with external reset feed been (Pid Er Fb) Ratio control (Ratio Ctrl) Switch Auto Manual 8) Process Module Points: Used for control language interface

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9) Device Control Point: It is a combination of Digital composite and logic point. 10) Array Point: It is used for third party PLC interface through SI

APM SOFTWARE CONFIGURATION: The APM software capacity is defined in terms of P U’s or processing units. One APM has 160 P U’ s. Each software point consumes a certain number of PV’s based on the type and scan rate. Point Type 1 sec ½ sec ¼ sec Regulator control 1 PU Regulatory PV 1 PU Digital composite 0.1 PU Logic 1 PU Process Module 1 PU length (to be configured while configuring APM)

2 PU 4 PU 2 PU 4 PU 0.2 PU 0.4 PU 2 PU 4 PU (OR) 2 PU based on sequence

This means that if the APM is configured to have only regulatory control points at 1 sec scan rate:

Then a max of 160 controllers can be configured.

½ sec scan rate: Then a max of 80 controllers can be configured. ¼ sec scan rate:

Then a max of controllers can be configured.

SCAN Rate: The Scan rate indicates the number of times that all slots of that particular type are scanned and processed each second. Fast slots (applicable for regulatory control, regulatory PV, digital composite Device control or logic categories are processed at a quarter second rate irrespective of the scan rate for the rest of the group. The fast slots are always the lower numbered slots.

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Entry for scan rate parameter

Reg ctrl ,Reg PV slots,

logic, DC, Device cntrl, PM

Reg 1 Log 1

1 sec

1 sec

1sec

Reg 1 Log 2

1 sec

½ sec

1sec

Reg 1 Log 4

1 sec

¼ sec

1sec

Reg. 2 Log 4

½ Sec

¼ sec

1sec

Reg. 2 Log 4

½ sec

¼ sec

1sec

Reg. 4 Log 4

¼ sec

¼ sec

1sec

Memory: The APM has 15,000 MU’S (Memory Units). The memory units are allocated as follows. POINT TYPE MEMORY UNITS/SLOT Regulatory Control Regulatory PV Digital Composite Logic Device Control Process Module String Numeric Flags Array Timer

13 12 5 15 30 15 1/8 1/16 0 8 0

Based on the plant requirement the optimum point mix is decided without exceeding the maximum number of each type specified below: SLOT TYPE Digital Composite Device Control Logic Slot Process Module Regulatory PV Regulatory control Array Numeric String

MAX NUMBER OF SLOTS 160 80 80 160 80 160 256 16,384 16,384

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LOGIC MANAGER: (LM): Lm provides high-speed logic functions on UCN. Its typical features are: * Fast logic program execution * Extensive digital, Boolean and interlock logic capacity * Ease of ladder logic programming Because of its position on UCN, LM shares some of the special features of its peers such as APM, HPM and sm. These include: * Peer to peer communications * Full communication with operator at us * Supports high level strategies through AM on LCN * Database restoration from HM PROCESSOR RACK: The processor rack includes the chassis, backplane and front plates. The processor modules are vertically positioned in the racks with component side towards the left. Backplane connectors are offset to prevent inserting a module upside down. The rack fits into an 8-inch NEMA 12enclosure or a 19-inch instrumentation rack. The diagram of the processor rack is as shown in the next page. There are 14 module slots which are configured as follows: A – OPTIONAL MODULE B – OPTIONAL MODULE C - OPTIONAL MODULE D - OPTIONAL MODULE E - MEMORY MODULE F - REGISTER MODULE G – SYSTEM CONTROL MODULE H – PROCESSOR MODULE I - I / O CONTROLE MODULE J & K – POWER SUPPLY MODULE L – SERIAL LINK MODULE M – SERIAL LINK MODULE N – PARALLEL LINK DRIVER MODULE OPTIONAL MODULES: 1. LMM: LOGIC MANAGER MODULE . Communication between processor and TDC 3000 UCN enabled . Communication between other logic Managers and Process Managers on same UCN is enabled. 2. RCM: REDUNDANCY CONTROL MODULE . Communication between 620-35 Processor and redundant rack enabled.

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INPUT&OUTPUT MODULES INTERFACING WITH LOGIC MANAGER

FIG 3.8,3.9

18

MEMORY MODULE(MM) The Memory Module stores the user control program. The green status LED, labeled PASS, located on the front of the module energizes after successful completion of the module self-test. The memory module is card rack slot C in the 620-25 and E of the 620-35. Additional memory modules can be inserted in option slots A – B in the 620-25 or slots A – D in the 620 – 35 to increase memory capacity to 32K. The memory starting address must be set for each module, forming contiguous memory space in order for a complete memory scan to occur during operation. REGISTER MODULE (RM) The Register Module contains the systems I/O Data Table. The data table is divided into three areas the I/O status Table, System Status Table, and the Register Tables. The I/O status table contains either 2048 (2K X 2K) or 4096 (4K X 4K) continuous single bit storage 2 K X 2K Register module 2048 single bit locations are 4K X 4K register module 2048 locations are available for real I/O status or internal coils, and an additional 2048 locations are available for internal coils. Timer and counter preset and accumulated value are stored in the register area. Other numerical data may be stored in the bit or register area The register area is 16 bit s wide plus a sign bit. The 17th bit is normally used to indicate the sign of the data contained in the register. In certain operations will indicate overflow conditions. The system status table stores processor diagnostic information that can be accessed by the loader/terminal or by the PULL instruction in the control program. The system status table consists of memory locations 8 bits wide. The table is divided into three sections: system diagnostics, system hardware status and system identification. The data table is battery backed to ensure data retention during system power out Stages. All register addresses are cleared to 0 when a total memory clear operation is executed. The register module is installed in slot D in the 620-65 and slot F in the 620-35. The green LED labeled PASS energizes after successful completion of the module self test.

19

LM Functional Architecture

Control Processor I/O Data Tables

FIG 3.10,3.11

20

SYSTEM CONTROL MODULE (SCM) The system control module, a functional extension of the processor module. Coordinates the interaction of all the modules in the process. The SCM also contains a single bit processor that solves all relay logic in the control program. The SCM is installed in rack slot E in the 620-35. A status indicator is located on the front panel of the SCM. The green LED labeled PASS energizes after successful completion of the self-test. PROCESSOR MUDULE(PM) The processor module executed the program stored in the memory module and handles arithmetic computation and data movement instructions. The processor module is installed in slot F in the 620-25 and slot H in the 620-35. Two status indicators are located on the front of the PM. The green LED labeled PASS energizes when the module passes its self-test. The red LED labeled TESTING energizes when the series of diagnostic tests are initiated on system power-up. The testing LED appears to remain energized as long as the processor is scanning since a short series of diagnostics, which occurs at the beginning of each scan, continually activates it. The port labeled loader/terminal connects to the 62351 loader/terminal connects to the 623-51 loader terminal and is protected by a removable cover plate.

I/O CONTROL MODULE (IOCM) The Input/Output control module coordinates communications between the processor and the system and formats the data flowing between the system and the processor. It also monitors individual I/O module fault diagnostics. The IOCM works in conjunction with the parallel link driver module and or serial link module to control data flow to I/O. The IOCM is installed in slot G and in slot I. POWER SUPPLY MODULES (PSM) The power supply module provides power operate the processor. The PSM is installed in slot H and in slot J. The module occurs the space of two processor rack in slot H and in J & K. A battery Compartment in the PSM contain lithium battery which provides back up power to a memory and register modules. The PSM is shipped with the battery installed.

21

PARALLEL LINK DRIVER MODULE (PLDM) The parallel link driver module works with the IOCM module to control I/O communications. The PLDM also controls system status by the mode key switch and it determines I/O response to system faults and various operating parameters. The PLDM is installed in slot N processors. The front panel of the PLDM contains three LED status indicators, a processor mode key switch and a D connector that interfaces the processor with the I/O system. The green LED labeled RUN energizes while the processor is scanning the ladder diagram program and it is operating correctly. The red LED labeled force energizes when at least one address in the program is in the forced state. The green LED labeled PASS energizes when the PLDM has passed its self test. The processor key switch has four positions for selecting processor mode of operation the positions are labeled PROGRAM, DISABLE, RUN/PROG and RUN. The DIP switch banks are located on the top edge of the PLDM. The banks are labeled SW 1 (four switches) and SW2 (eight switches). The switches select the I/O response to system faults and various operating parameters. SERIAL LINK MODULE (SLM): The SLM front plate has five LED’s indicating the status of the module. The operating states of the SLM are shown by the status of the front panel LED’s. The green active light indicates that data is being transmitted properly. The normal state of the light is ON during transmission. There is one of these LED’s for each channel. There is a yellow link fault LED for each channel. It indicates that rack fault or a communications fault has occurred on the channel. The normal state is OFF. When a link fault occurs, the LED turns ON. It remains ON as long as the problem exists winless power is cycled at the SLM or the serial system in which the fault exists is reset by shorting the reset terminals at the SLM. After the SLM has bee reset or hard power cycled, the serial system re-initializes. This includes the drops taken off line, except those that have been manually powered down because of the fault, and the link fault LED OFF. The LED remains ON if the faulted racks are restarted by a means other than resetting or cycling power at the SLM.

22

FIG 3.12 16 I/O RACKS PER CHANNEL 1300M WITH BELDEN-9729 3300M WITH BELDEN-9182 MAX. REAL I/O’S-2048

23

24

REDUNDANT LOGIC MANAGER’S UCN-A

UCN-B DATA CABLE

A B L M M

D E F C R B M R C L M M M A N K

G

H

I

S P I C M O M C M

J K P S M

L

M

S B L L M A N K

N 2 1

3 4

PLD

SWITCHING CABLE

A B

D E L M M

C R B C L M A N K

F

G

H

I

M R S P I M M C M O M C M

SWITCHING CABLE

25

J K

L

P S M

S L M

M N 2 1

3 4

PLD

FIGURE3.13

SERIAL AND PARALLEL COMMUNICATION AB

C

L M M

R C M

D B L A N K

E

F

M M

G

H

S C M

R M

I

J K

L

I O P C S M M

P M

N

S L M

M B L A N K

C

D

E

F

G

H

I

J K

L

M

N S I O M

D D I I

D I

D I

D I

D I

D I

D O

D O

D O

D O

P S M

A B

C

D

E

F

G

H

I

J K

L

M

N

A O

P S M

S I O M

D D I I

D I

D O

D O

A I

A I

A I

A I

A O

2 3 4

PLDM

CH-2

CH – 1

A B

1

T0 FURTHER I/O RACKS

A B

D D I I

C

D I

D

D I

E

D I

26

F

D I

G

D I

H

D I

I

D O

JK L

M

N

D O

P S M

P I O M

D O

A B

C

D

E

F

G

H

I

JK L

M

N

D D I I

D I

D I

D I

D I

D I

D I

D O

D O

P S M

P I O M

FIG 3.14

D O

T0 FURTHER I/O RACKS

CHAPTER-3 ALGORITHM LIBRARIES 1.Regulatory PV Point: While standard I/O functions such as engineering unit conversion and alarming are handled directly by the I/o processors, Regulatory PV (reg. PV) points provide an easy to use configurable approach for implementing PV calculations and compensation functions. PV processing provides a menu of the following selectable algorithms: Data Acquisition (DataAcq) Flow Compensation (Flow Comp) Middle of 2 selector (MidOf3) High Low Average Selector (Hiloavg) Summer (summer) Variable Dead Time with Lead Lag Compensation (VDTLDLG) Totalizer (Totalizr) General Liberalization (gentian) Calculator (Calculator) At least one input connection must be configured for any selected algorithms input otherwise the point cannot be made active. 2.PV Algorithms: Data Acquisition This algorithm does not alter the input value at all. The value accepted from the defined source is put in PVCALC. The most common use of this algorithm is to provide a PV that has been through PV Input processing, PV Algorithm Processing, PV Filtering and PV Source selection. The input can be a measured process-variable or the calculated output of another data point. Flow Compensation

27

This algorithm compensates a flow measurement for variations in temperature absolute pressure, specific gravity or molecular weight. The measured flow can be that of a gas, a vapor or a liquid. An extended equation is provided for industrial steam flow compensation, which includes factors that compensate for steam quality and compressibility. The compensation is calculated from temperature, pressure, specific gravity, molecular weight, steam quality or steam compressibility one or more of these variables being used dependent on the requirement.

Middle of Three Selector (MidOf3) This algorithm provides a calculated PV (PVCALC) that is normally the middle value of 3 values from the PV input connections. When configured with only 2 inputs it serves as a high / low selector or input averaging block. This algorithm is used to provide a reasonably secure PVCALC when inputs are available from 3 redundant inputs, one or more of which may occasionally fail or provide erratic values. It can be used in an application like reading signal from duplex or triplex thermocouple High Selector, Low Selector, Average (HILOAVG) This algorithm can select the highest, the lowest or calculate the average of unto 6 inputs it accepts. The data point can be configured to allow The US operator, a user written program or a general input connection to force selection of one of the inputs. It can be used to detect hot spots in a boiler or a reactor or in balancing furnace passes by calculating the average of the outlet temperatures of the passes. It might be used to select the safest PV for control. Summer (SUMMER) This algorithm calculates a PVCALC that is the sum of unto 6 input values. The input values can be scaled, the combined inputs can be scaled and a bias value can be added to the result Using a negative scale factor can use it). Other possible uses are mass balance heat balance and inventory calculations. Variable Dead Time with Lead Lag Compensation This algorithm provides a calculated PV (PVCALC) in which value changes may Dynamic lead lag compensation with or with out the delay. The delay time can be 28

fixed or can be varied as the value and in process simulations. It can also be used as the PV algorithm in a data point that uses the PID Feed forward control algorithm. In a typical feed forward application, the PV provided by this algorithm serves as the feed forward PV. Totalizer (TOTALIZER) This algorithm provides a time scaled accumulation of an input value. Either analog or pulse input can be selected. The time base can be seconds, minutes or hours. The accumulation can be started, stopped and reset by commands from a operator or from a user written program.

For situations where the flow transmitter may not be precisely calibrated near the zero flow value, a zero flow cut off feature is provided that avoids accumulating negative flow values. If the flow is below a sera specified cut off value can be used for control or just as process history. General Linearization (GENLIN) This algorithm calculates a PV that is a function of the input. The function can be any that can be represented by up to 12 continuous linear segments. You specify the base and slope of each segment. The input is compared with the input range of each segment and the output is set at the intersection of the input with the appropriate segment. The slope of all segments shall have the same sign. A zero value for slope IOUs allowed but reversal is not It is typically used to provide a linearized PV (in engineering units) for a sensor with a nonlinear characteristic. This algorithm can also be used to characters functions of a single variable, such as heat transfer Vs flow rate or efficiency as a function of load. Calculator (CALCULTR) The calculator algorithm allows the user to write an equation to compute the PV and up to 4 intermediate results. The result from evaluating the expression is stored into PVCALC, which is then processed like any other algorithm. The following general guidelines apply: The equation can be up to 40 characters long. FORTRAN like syntax rules apply Up to 5 levels of nesting of expressions Free format real and mixed real and integer calculations permitted Up to 4 intermediate results allowed The result of any expression that has no “equate” associated with it is stored into PVCALC.

29

This algorithm can be used to perform any calculation or arithmetic function on up to 6 inputs, using up to 4 intermediate results. 3.Regulatory Control Point Regulatory Control (Reg. Ctrl ) points are used to perform standard closed loop control functions by executing the algorithms that have been configured. The following control algorithms are available under this category. PID PID with external reset feedback Position proportional PID position proportional Ratio control

Ramp soak Override selector Auto manual Incremental summer Switch Null Before starting the discussion of the algorithms, we will first acquaint ourselves with some important provisions of APM 3.1 Modes: The following operating modes are applicable to the Regctl point: Manual (MAN) – provides the operator or the discontinuous program with direct control over the output value of the data point, regardless of any automatic control strategy. Automatic (AUTO) – output value is computed by the configured regctl algorithm, and the setpoint comes from the local set point (LSP) location in the Regctl point. An operator or discontinuous program can change the set point value. Cascade (CAS) – data point receives its set point value from a primary data point. 3.2 Mode Attribute The mode attribute denotes who has the authority to change certain parameters of a data point and is established through parameter MODATTR. The mode attributes are as follows: Operator : operator can supply the set point, output value, mode, ratio, and bias for a data point (operator – access level) Program – program can supply the set point, output value, mode, ratio and bias for a data point (program-access level) 3.3 a Bad PV/Mode shed:

30

The Regulatory control parameter BADCTLOP determines if the mode sheds to manual on detection of a bad PV. This function does not apply to the ramp soak. Incr Sum or RatioCtl algorithms. 3.3 b.SP target Value (SPTV) This option allows a universal station operator or a user-written program to ramp the set point from the current value to a new value over a period of time. The option is configured through the data entry builder by entering TV in set point option parameter SPOPT. It can also be configured on-line if the engineers access is available.

To use the SPTV option, the operator 1. enters the desired new SP value in SPTV 2. Enters the ramp time (in meters) in RAMPTIME. 3. Enters run in TVPROC 4. The SP begins moving linearly towards the new value and the value in RAMPTIME decreases with time. When RAMPTIME = 0 SP reaches the new value and the status in TVPROC changes to off. PVPROC can be used only in AUTO mode 3.4 PV tracking (PID Algorithms) PV tracking is configured by entering track for the PVTRACK parameter. During PV Tracking. SP is set equal to PV whenever the cascade is broken by an operator or a program action. PV tracking is not performed if the mode of data point is Auto. Note than PV tracking (even if configured) is not done on return from a Bad PV in R410 and later systems. 3.5 Control initialization Control initialization allows normal control strategies to be re-established after they have been interrupted, without “bumps” in the output to the process and without the need for manual balancing of values to avoid such bumps. Initialization is indicated on the US in group display or detail display with INIT appearing in the point status field which is just below the mode indicator. The initialization procedures automatically readjust either the bias value in the data point(s) or an input to the data point(s) (depending on the algorithm used) so that when normal control is re-established the output to the process does not move or bump. The new value is back-calculated for an input that shall absorb any output change. This value and an initialization request are sent to the primary data point that provides the input. Thus the primary absorbs the change and it must take similar 31

action with its own primary. If is has one so that the whole strategy can absorb the change. By configuring a control output connection from one point (primary) to an initializzable input of another point (secondary) an initialization path is created it is along this initialization path that a value transferred for use to a primary to absorb external process upsets that may have occurred at the secondary. Two or more active paths from a single primary to multiple secondaries are referred to as fan out connections. Where there are two or more control output connections from a primary to two or more secondaries and all of these outputs are in disposable only then the primary goes into initialization state.

The value that is to be protected from a bump (the value to back-calculate form) is obtained at the point’s output or at the secondary’s initializable input. The need to initialize a data point is indicated by external upsets that directly affect the point or is indicated by an initialization request from a secondary data point. Control initialization is caused by any of the following : * The point is active for the first time (an inactive to active transition) * The point is executing the first time after a warm APM restart. * All control output connections were in disposable and now one or more output connections is disposable. A control output connection is said to be in disposable when *A secondary has made an initialization request. *A communication/configuration error has been detected in retrieving an initialization value from a secondary. The following are the reasons why a secondary data point sends an initialization request to primary data point: * The secondary is inactive. * The secondary isn’t in cas mode. * The secondary is in the initialization state. 4.Control Algorithms 4.1 PID (Proportional, Integral and Derivation):

32

This algorithm operates as a standard PID controller. Error is represented by the difference between the process variable (PV) in percent and the set point (SP) in percent. The control algorithm output value (CV) is also calculated as a percentage of the configured engineering units range for the data point that uses this algorithm. The PID algorithm is used as a controller that either directly moves a control device (valve) in the process or provides as input to another data point. The default for the number of inputs is 1 : however, it can be increased to 2, allowing the SP to be fetched with an input connection. When the SP is fetched, the normal operating mode of the point is usually affected.

When the PID point is primary for another data point, its output is connected to the SP of the other data point through Tag name Parameter which is to be the secondary. If the PID point is directly controlling a valve, its output is connected to the output of an analog or digital IOP through Tag name Parameter or the hardware reference address. Interactive (Real) form – This form emulates traditional pneumatic PID controllers. The P,I and D terms are calculated as the resultant of D acting on the sum of the results of P and I acting on the error or PV changes. Non-interactive (Ideal) Form – In this form, P, I and D act independently on the error or PV changes and are then added algebraically in the time domain. D is pure derivative. This form is often called the digitalcomputer version of the PID controller. A choice of 4 combinations of Control terms is available – Equation A – P, I and D act on the error. Equation B – P and I act on the error while D acts on PV changes. This equation is used to eliminate derivative spikes in control action that occur with quick changes in the SP. Equation C – I acts on the error while P and D act of PV changes. This equation provides the smoothest and slowest response to SP changes. Equation D – this equation provides only I action. You can also select the type of control action – Direct control action – An increase in PV increases output. Reverse control action – An increase in PV decreases output.

33

Changing the control effectively changes the sign of the gain. The control action can be changed at the Us or by a program only while the data point is in man mode. The requirement of the process governs the types of control action used while the type of valve (air- to-open or air –to-close) depends on the control action selected. Gain Option When configuring a data point that uses the PID algorithm and equations A,B orC : you can choose any of the following four gain options. * Linear Gain – This is the most commonly used gain option. The gain, K used in the chosen equation is set by the user.

* Gap Gain Modification – This option issued to reduce the sensitivity of the control action when the PV is in narrow band (gap) around the set point. The size of this band is specified by the user. * Non-linear Gain Modification – This option provides control action proportional to the square of the error, rather than the error itself. * External Gain Modification – The gain K, used by the chosen equation is modified by an input value that can be from the process, from a PV calculated from a process input by a PV algorithm or from a user-written program. The main use of this option is to compensate for nonlinear process gain. The user can tune the PID gain independently of the operating point of the process. For example, in the controlling the level in a tank whose cross section is not constant, the gain could be modified to compensate for the nonlinear rate of level change that is caused by the changing shape of the tank. Windup Handling When the output of this algorithm reaches the user-specified output limits or reaches the set point limits of the data point’s secondary or when a windup-status indication is received from the secondary the integral action of the PID algorithm stops but the proportional and derivative actions continues. Bias Options Ratio control can be obtained by modifying the set point input to the PID algorithm by a RATIO of some other process point that is stored through a control output connection, for example a fuel-to-air ratio in furnace control (it can also be accomplished with the Ratio Control algorithm) 4.2 PID with Feed forward (PIDFF): This algorithm is identical to the PID algorithm, except that is accepts a feed forward signal to be added to or multiplied by the algorithm’s incremental output before the

34

full-value output is accumulated. Unlike the PID algorithm this can accept a dynamic feed forward signal from the process. The 3 inputs to this algorithm are a PV a FF signal and if required a SP If additive feed forward action is chosen, the feed forward signal is multiplied by a user-specified scale factor (KF) and added to the incremental output of the PID computation. If multiplicative feed forward action is chose, the feed forward signal is multiplied by the scale factor (KF) and then multiplied by the full value output of the PID computation. If the value status for the feed forward signal goes bad, the feed forward component of the output value is frozen at the last good value and normal PID processing continues.

4.3PID with External Reset-feedback (PIDERFD) This algorithm operates as a PID controller, except that is accepts a Reset feedback signal to be combined with it’s incremental output, before the full-value output is accumulated. It also accepted a tracking-value signal to prevent windup when it has a secondary data point, typically a PID point. This algorithm requires 3 input connections : a PVAUTO signal a reset feedback value typically the PV or SP (as per strategy design) of its secondary. The tracking facility is controllable through an external logic. If the secondary is not accepting the signal from this point then the output of this point tracks the PV of the secondary so there is no bump and normal control can resume when the cascade is re-established. That is initialization occurs only if driven externally. 4.4 Position Proportional Controller (POSPROP) : This algorithm manipulates two digital outputs, raise and lower to drive the PV toward the SP. The set point is typically the desired position of a valve and the PV is the actual feedback from the position indicator on the valve. Digital outputs are pulsed at a time interval specified by the CYCLETIME parameter and the pulse width is proportional to the error signal. This algorithm would typically be used to step a valve open or closed to raise or lower a rotary device or to move plates of a pulp mill refiner together or a part. Output manipulation in manual modeAt the time of configuration, the pulse time must be defined for manual control of the output (MANOPTIM) Windup feedback Limit switchesOutput High and Low flags can be set to indicate the status of the limit switches representing the valve position. When OPHIFL is set the raise output pulses are 35

inhibited when OPLOFL is lower output pulses are inhibited, OPHIFL and OPLOFL are set through external logic. 4.5PID Position Proportional Controller (PIDPOSPR) This algorithm can be viewed as a normal PID algorithm joined in cascade with a posprop algorithm such that the posprop part uses the output of the normal PID as its PV to generate raise and lower pulses. The function of the PID part of the algorithm is the same AS THAT OF THE NORMAL pi ALGORITHM EXPECT THAT pidpospr does not support OP (and OP related parameters OPEU, OPHILM etc) and CV (and CVEUHI< CVEULO) the end part of the algorithm behaves exactly as a posprop algorithm.

4.6Ratio Control (RATIOCTL) This algorithm calculates a set point for a PID algorithm that is controlling the flow of a material as a ratio of another which is the wild flow. The output of this algorithm is calculated from the operator given ratio and the wild flow value. This algorithm is typically used in the control of the flow of a gas or fluid, SD s ratio of an another flow, for eg in a furnace the air supply might be controlled as a ratio of the fuel supply. If more heat is required to maintain combustion efficiency the fuel flow is increased and the air flow can be increased as a ratio of the fuel flow increase. This algorithm required 2 input connections PV the actual ratio from PV calculator algorithm andX2 uncontrolled variable and accepts the operator or user program defined set point. 4.7Ramp and Soak (RAMPSOAK) This algorithm is typically used as a set point programmer. It produces an output that consists of up to 12 alternate ramp and soak periods total 24 augments RAMPSOAK is principally used for automatic temperature cycling in furnace and ovens. It can also be used for automatic start up of units, and for simple batch sequence control where the batch sequence is part of a process that is otherwise a continuous process. Single or Cyclic Sequencing Once started the configured sequence of ramps and soak periods repeats itself if it is not stopped by an operator or by a user written program. A US operator can put the point in Man mode to freeze the sequence and then return it to Auto mode to continue the sequence. When in Man mode, the operator can change the remain in soak time if the current segment is a soak. He can also change the current segment, when the mode is returned to auto the sequence continuos as modified by these

36

changes if the segment was changed the sequence resumes with the new segment, which can be a ramp or a soak. 4.8 Auto Manual (AUTOMAN) In cascade mode this algorithm calculates a control output that is equal to the input valve plus a bias value. The bias value is normally provided by a US operator. In manual mode, the output is controlled by a US OPERATOR OR A USER WRITTEN PROGRAM. Equation A provides dumbbells returns to cascade operation, even through its primary data point may not accept the initialization value from the AUTOMAN data point. Equation B provides automatic balancing of the biases between several auto manual stations and bumbles closing of a cascades with ramping of the initialization component. It is typically used in split range control applications.

5. Incremental Summer (INCRSUM ) This algorithm calculates the sum of the incremental changes in up to 4 input values. The output is obtained by adding the sum of the changes in all inputs, after each input is multiplied by a scale factor. This algorithm is typically used where more than one primary data point is used to man epaulet the set point of the same secondary data point, the primary usually uses PID algorithms, and are connected to an INCRSUM data point. The output from the INCRSUM data point is connected to the secondary. 6 Switch (SWITCH): This algorithm operates as a single pole 4 position rotary switch. An operator at a US (Equation A) a user written program or user configured logic (equation B) can change the position of the switch, thereby selecting any one of the 4 inputs to be the control algorithms output value CV. You can configure the SWITCH algorithm for the tracking option, which causes non selected inputs to track the selected input value. This allows the switch position to be changed without Bumping the output. When tracking option is configured, the primaries connected to non selected inputs can be initialized. 7.Override Selector (ORSEL): The Override selector algorithm is used with up to 4 PID inputs, all of which are intializable. The input with the highest value or the input with the lowest value is selected and passed on to the output of this data point. PID data points connected to non selected inputs are prevented from winding up by forcing their outputs to track the override feedback signal (ORFBSEC) 8.Logic Point: The logic point provides a configurable mix of logic capability that together with a digital composite point provides the basis for internal logic functions. A logic point consists of logic blocks, flags, numeric, user defined generic descriptors, inputs connections, output connections and their enabling definitions. The three options of LOGMIX parameter are 12-24-4, 12-16-8,12-8-12. The first number indicates the no of input connections possible. The second number indicates

37

the no of logic blocks that can be defined for the tag being built. The last number indicates the no of output connections possible. The input connections can accept signal from any of the following: 1. Any Boolean, integer or real parameter within this APMM or in another UCN node on the same UCN 2. The PVFL parameter of a DI point. 3. Any parameter from the IOP’S in this APM The Generic Descriptors are used to describe the important parameters of the particular logic point.The output connections require that the parameter inside the logic point be defined as the source of connection, a POINT PARAMETER be defined as the receiver or destination of connection and a parameter inside the logic point be defined as the enabling signal for the connection to be made. Output destination can be Integer, Real or Boolean in the same node or any other node on the same UCN Shown on the following page are the parameters internal to the logic point.

The conceptual structure of the logic point is as shown below. This is the structure available under ONE tag. FIGURE 4.1 LISRC (1) LISRC (2) LISRC (3)

L1 L2 L3

LISRC (4) LISRC (5) LISRC (6)

L4 L5 L6

GENERIC DESCRIPTORS 12 Nos.Point Build set

FLAGS

LOSRC (1) LOSRC (2) LOSRC (3)

LODSTN (1) LODSTN (1) LODSTN (1)

LOSRC (4) LOSRC (5) LOSRC (6)

LODSTN (1) LODSTN (1) LODSTN (1)

LOSRC (7) LOSRC (8) LOSRC (9)

LODSTN (1) LODSTN (1) LODSTN (1)

LOSRC (10) LOSRC (11) LOSRC (12)

LODSTN (1) LODSTN (1) LODSTN (1)

1-6 Pre-defined :7-12 User set

LISRC (7) LISRC (8) LISRC (9)

L7 L8 L9

LISRC (10) LISRC (11) LISRC (12)

L10 L11 L12

NUMERICS 8Nos. User Set

ALGORITHMS Point Build set

LOENBL (1) ~LOENBL (12)

The logic points are used for establishing the PROCESS INTERLOCKS in a process. They are also used for establishing communication between two UCN nodes on the same UCN .

38

Every logic point is provided with four custom alarms having an 8 character descriptor. The alarm source can be any of the following L1-L12, FL1-FL12,SO1SO24. The following logic block algorithms are supported. Null (NULL) AND gate (AND) OR gate (OR) NOT gate (NOT) NAND gate (NAND) NOR gate (NOR) XOR gate (XOR) Qualified OR gate with 2 inputs ON (QOR2) Qualified OR gate with 3 inputs ON (QOR3)

Switch (SWITCH) Compare equal with dead band (EQ) Compare Not Equal with dead band (NE) Compare Greater than with dead band (GT) Compare Greater than or Equal with dead band (GE) Compare Less than or equal with dead band (LE) Check for Bad (CHECKBAD) Fixed size Pulse (PULSE) Pulse with Maximum time limit (MAXPULSE) Pulse with Minimum time limit (MINPULSE) Delay (DELAY) On Delay (ONDLY) Off Delay (OFFDLY) Watchdog Timer (WATCHDOG) Flip-flop (FLIPFLOP) Change Detect (CHDETECT) We will now discuss features of these algorithms Logic Algorithms 1. Null (NULL) This algorithm provides an output (SO) that is always set to OFF 2. AND gate (AND) This is a 3 – input (S1, S2, S3) AND gate with input inversion option. All three inputs need to be defined. 3. OR gate (OR) This is a 3 input (S1 , S2, S3) Or gate with input inversion option. All three inputs need to be defined.

39

4. NOT gate (NOT) This algorithm provides Boolean inversion. Single input. 5. NAND gate (NAND) This is a input (S1 , S2 , S3) NAND gate with input inversion option, All three inputs need to be defined. 6. NOR gate (NOR) This is a 3 – input (S1, S2, S3) NOR gate with input inversion option. All three inputs need to be defined.

7. XOR gate (XOR) This is a 2 – input (S1, S2) Exclusive or gate with input inversion option. 8. Qualified OR gate with 2 inputs ON (QOR2) This is a 4 – input ( S1 , S2 , S3 , S4) qualified Or gate providing 2 cut of 4 function. 9. Qualified OR gate with 3 inputs On (QOR3) This is a 4 – input (S1, S2, S3, and S4) qualified or gate providing 3 out of 4 function. 10. Switch (SWITCH) This is a 3 – input (S1, S2, and S3) algorithm with the third input acting as the router if it is on, the first input is routed to the output otherwise, and the second input is routed. 11. Compare Equal with dead band (CE) This algorithm compares between two real inputs (R1, R2) for being within a specified dead band from each other). 12.CompareNot Equal with dead band (NE) This algorithm compares between two real inputs (R1, R2) for not being within a specified dead band from each other.

40

13. Compare Greater Than with dead band (GT) This is a 2 – input (R1, R2) algorithm. It compares the first input with the second input in following manner. If R1>R2, SO is ON else if R1 = (R2 + dead band) SO is OFF.

16. Compare Less than or Equal with dead band (LE): This is a 2 – input (R1 , R2) algorithm. It compares the first input with the second input in following manner. If R1>>>>>>>>> POLNT : SOUNTRWD (1)

AREA : 01

56

PAGE 1 OF 4

PATHNAME CATALOG CONFIGURATION BUTTON CONFIGURATION FILE :

VOLUME ID FILE NAME

SCHEMATIC OR FFL PATHNAMES (DEVIC>VOLUMR) ( SEARCHED LEFT TO RIGHT, TOP TO BOTTOM ) :

MEMORY RESIDENT SCHEMATIC OR FFL FILE NAMES (LOADED LEFT TO RIGHT, YOP TO BOTTEM ) :

F1 = PED F6 =

FFL

FFL

FFL

FFL

FFL

FFL

FFL

FFL

FFL

FFL

FFL

FFL

FFL

FFL

FFL

FFL

FFL

FFL

FFL

FFL

FFL

FFL

FFL

FFL

FFL

FFL

FFL

FFL

FFL

FFL

F2 = RECALL DISP F7 = WLK BACK

F3 = F10 = WRITE

F4 = F11 = TAB

F5 = OVERWRITE F12 = LOAD

FIG 7.1 This display has provision for defining the Button configuration file that shall be loaded in the Universal Station when this area is loaded. It also provisions for defining the path through which the schematic displays shall be searched on call up. This path is through the Logical device (HM and / or Cartridge / Floppy / Zip drives) and the directory contained on the device. Some schematics and / or Free Format Logs can be “Memory Resident” The ‘FFL’ target shall be selected for keeping the FFL’s memory resident. The number will vary dependant on the S/W Release an the complexity of the graphics.

CHAPTER-7 COMMAND PROCESSOR The command processor provides a tool for the Engineer to carry out tasks related to the utilities provided in TDC 3000. 57

The command processor includes utilities (cl compiler, text editor etc) invoking commands and storage (HM and removable medias) handling commands. This is the instruction-response type of tool of the system.

ENGINEERING MAIN MENU UNIT NAMES

HIWAY GATEWAY

PICTURE EDITOR

AREA NAMES

LOGIC BLOCKS

FREE FORMAT LOGS

CONSOLE NAMES

APPLICATION MODULE

LCN NODES

COMPUTING MODULE

BUTTON CONFIGURATION HM HISTORY GROUPS

SYSTEM WIDE VALUES

NETWORK INTERFACE MODULE

VOLUME CONFIGURATION BUILDER COMMANDS

DOCUMENTATION TOOL AREA DATA BASE

SUPPORT FUNCTIONS AND UTILITY PROGRAMS COMMAND SYSTEM PROCESSOR MENU SUPPORT UTILITIES

SYSTEM STATUS

CONSOLE STATUS

SMCC/MAINTENANCE R510©HONEYWELL INC 1984-96 FIG 8.1

When you touch the command processor option (highlighted above) on the engineering personality main menu, it will open up a blank screen with two regions. The lower two lines form the command region and the section above is the response region. You can type instructions in the command region only and not in the response region. On the right hand top of the screen, you will find the presently set default path you will be using the command processor utility to a large extent while working on control

58

language. The editing completion a fault locating removal and copying of the object files are the operations required while working on CL. The following switches are used with different command of the command processor. NOTE 1. Volume or directory name can be of maximum 4 characters. 2. File name can be of maximum 8 characters. 3. One volume can have maximum 63 directories. 4. One cartridge/floppy can have maximum 1 volume. 5. All system volume or directories’ names start with “!”or”&”. 6. File extensions are maximum 2 characters. 7. Command processor is “not case sensitive”. The command processor is used to invoke utilities for programming customized controls in control language. The editing, compilation, fault locating-removal and copying of the object files are the operations required while working on cl. The following switches are used with different commands of the command processor. -NX : Instructs the complier that cross reference table is not to be generated for the program under compilation. NO CROSS REFERENCE _NL : Instructs the compiler that listing of the executable statements is not to be generated for the program under compilation. NO LISTING -UL : Instructs the complier that the program name and names of phases, steps are to be updated into the Network Library. UPDATE LIBRARY. -D : Instructs the command processor that the progress of the command given shall be displayed during the execution of that command. -F : Format -MF : Maximum number of files

IMPORTANT COMMANDS 1. LSV NET : Lists all volumes and contained directories on the HM 2. LS $F1 – D : Lists all volumes and contained directories on the cartridge.

59

3. LS NETor$F1>PICS> *. * : Lists all files in the PICS directory / volume on HM or on Cartridge. 4. CR $f1>VOL1.-F – MF 2000 : Formats the cartridge or floppy in drive F1 with name VOL1. The maximum number of files that may be stored in this volume is 2000. 5. CD NET or $F1>VOL1> DIR1: Creates a directory DIR 1 under the volume VOL 1 on HM or cartridge or Floppy in drive 1. 6. CP NET or $F1>PICS>8.* NET or $F1>DEST. = -D : this command copies all files in PICS volume or directory on HM or on cartridge or floppy in drive 1, with same names to the DEST volume or directory on HM or cartridge or floppy in drive 1. 7. DL NET > VOL1 > Q*.* : Deletes all files with names starting with Q regardless of their extensions from VOL1 volume or directory on HM 8. S P NET>TEST> : Sets default path to TEST volume or directory on the HM 9. DD NET or $F1>VOL1> DIR1: Deletes the DIR 1 directory from the VOL 1 volume on the HM or cartridge or floppy in drive 1. 10. RN NET>VDIR>GEORGE.XX RALPH –D Change the name of George files, all extensions (suffixes),to Ralph (up to 8 characters for file names) 11. PROT NET>VDIR>HIC.* protect all hic files 12. UNPT NET>VDIR>HIC.* cancel protections for all hic files. 13. FCOPY $F1 $F2 in this floppy copy, $f1 is the source,$f2 is the destination. 14. CPV NET>VOL $F2>VOL –D –A A display files option (-D) lists each file as it is copied An all files option (-A) copies all directories in the volume. 15. EC DEV>VDIR>FILE.XX execute a command file. 16. ED DEV>VDIR>FILE.XX edit a file. 17. FN : find names menu. 18. END : exit the command processor.

CHATER-8 NETWORK CONFIGURATION OVERVIEW:

60

The NCF (Network Configuration File) provides a foundation for all other TDC 3000 system configuration and must be completed before entering other configuration data i.e. The project engineer from TATA Honeywell will be first completing the planning and definition of NCF before starting anything else on the TDC 3000 system manufactured for your project. Shown below is the engineering personality main menu screen. The highlighted options are the NCF constituents.

13 MAY 08 18:30:36 ENGINEERING MAIN MENU

5

UNIT NAMES

HIWAY GATEWAY

PICTURE EDITOR

AREA NAMES

LOGIC BLOCKS

FREE FORMAT LOGS

CONSOLE NAMES

APPLICATION MODULE

LCN NODES

COMPUTING MODULE

BUTTON CONFIGURATION HM HISTORY GROUPS

SYSTEM WIDE VALUES

NETWORK INTERFACE MODULE

VOLUME CONFIGURATION BUILDER COMMANDS

DOCUMENTATION TOOL AREA DATA BASE

SUPPORT FUNCTIONS AND UTILITY PROGRAMS

COMMAND PROCESSOR

SYSTEM MENU

SUPPORT UTILITIES

SYSTEM STATUS

CONSOLE STATUS

SMCC/MAINTENANCE

R510©HONEYWELL INC 1984-96 FIG 9.1

EDIT AREA NAMES

PAGE 1 OF 1 ONLINE

61

AREA NAME

AREA DESCRIPTION

ASC

AUTOMATION SOLUTIONS CTR

PWRGEN

POWER GENERATION

PAPER

PAPER

REFININ

REFINING

CHEMIC

CHEMICALS

SHOWS

TRADE SHOWS SPECIALS

REGION

REGIONAL AREA DATABASE

ENGINE

ENGINEER WOK AREA

ADVAN

ADVANCED

CED CUST

CUSTOMER WORK

F1 = CHECK F3 = SET OFFLINE

& PULP

F2 = INSTALL F4 = PRINT

F9 = PACK NCF

F11 = TAB

FIG 9.2

Area Names: – This target is used to define up to 10 area names. An area name is an identifier used in the system to designate an area database. An area is process equipment that can be monitored and controlled from a US. Typically, all the Us’s in a console are loaded with the same area database. This provides the console with display to support control of the area.

62

EDIT CONSOLE NAMES PAGE 1 OF 1 ON-LINE CONSDLE NUMBER 1

CONSOLE DESCRIPTION ASC DEMO ROOM

2 3 4 5 6 7 8 9 10 F1 = CHECK F3 = SET OFFLINE

F2 = INSTALL F4 = PRINT

F9 = PACK NCF

F11 = TAB

FIG 9.3

Console Names: – This target is used to define up to 10 console names. A console name consists of up to 24 characters that identify a console. A console is logical grouping of Us’s and associated equipment (peripherals). Console configuration permits sharing of screens and peripherals.

LCD NODE CONFIGURATION - SELECT DESIRED NODE PAGE 1 OF 4 ON-LINE

63

NODE NO 1 2 3 4 5 6 7 8

NODE TYPE

REDUNDANT N/P/S

US

NDE NO 09 10 11 12 13

US US

NODE REDUNDANT TYPE N/P/S

US US HM 14 15

US

.

F3 = SET OFFLINE F4 = PRINT

F5 = ABORT

F11 = TAB

FIG 9.4

LCN Nodes: – This target is used to define up to 96 nodes on the LCN. A node may be US, AM, HM, NIM, HG etc. A US and its peripherals are assigned to a console in this section. Similarly, the software or hardware contents of a node are defined in this section. Any special software that may be required is defined in this section.

UNIVERSAL STATION PAGE 1 OF 2 ON-LINE

NODE

64

MODE

1

CONSOLE 1 STATION AREA CARTRIDGE DISC NUMBERS

1 1

PAPER DEFAULT 2

FOLPPY DISC NUMBERS PRINTER NUMBER TREND PEN NUMBER VIEW

OPER

UP

OPER

STATION DEFULT ACCESS LEVEL STATION DEFULT LOAD PERSONALITY STATION OPTIONS OPERATORS NO YE KEYBORD

TOUCH NO YESCREEN

MODIFY NODE

F1 =CHECK F3 = SET OFFLINE F2 = INSTALL F4 = PRINT

ENGINEERS NO KB YE DELETE NODE

F5 = ABORT

F9 = PACK NCF

F11 = TAB

FIG 9.5

Shown above is the screen that you will get when you touch a box indication US in LCN NODE screen. Either Cartridge or Floppy drives can be connected to a Universal Station. Both also can be connected but this requirement is virtually non-existent. A printer can be defined and also the trend pen number if a trend pen recorder is to be connected to this Universal Station. The keyboards (Operator’s as well as Engineer’s) are optional just like the touch screen.

SYSTEM WIDE VALUES MENU ON LINE

65

SYSTEM ID

NG LOCAL SYSTEM ID

CLOCK SOURCE

NG REMOTE SYSTEM

USER AVERAGE PERIOD

NG SECUTITY

SHIFT DATA

NG MODEM DEGINITION

CONSOLE DATA

TAG NAME OPTIONS

SOFTWARE OPTIONS

F3 =SET OFFLINE F5 = ABORT

F9 = PACK NCF

F11 = TAB

FIG 9.6

System Wide Values – This target is used to define values and conventions that are available for use throughout the system. Since changes to the NCF require partial shutdown or restart: it is important to precisely define these values. Some of the options in these values are as under: 1

Clock source:– The system clock is maintained by two modes on the LCN. These nodes act as master and secondary clock sources and are defined from this target.

2

User average period: – This is used to calculate an average below the minimum standard as 1 Hour.

3

Shift data :– This defines the shift duration, start day of the first shift of the week, and start time of the first shift of the week, number of shifts per week. This data is used to calculate the shift, weekly and monthly averages. Console data: - This defines the key level requirements for many options. Many important options like who can shutdown a working LCN node, who can idle or shutdown PM, who can load the Universal or Engineer personality in a US are covered under the console data.

4

CONSOLE DATA PAGE 5 OF 11 ON-LINE

66

PHYSICAL NODE COMMAND ACCESS TABLE LOAD OPERATIONS NON US MODE (CG/NG/HM ONLY) OPE

SUPE

ENG

R

LOAD OPERATIONS LOCAL CONSOLE US

OPE

SUPE

ENG

LOAD OPERATIONS REMOTE CONSOLE US

OPE

SUPE

ENG

DUMP NODE

OPE

SUPE

ENG

OVERRIDE DUMP

OPE

SUPE

ENG

SHUTDOWN MODE

OPE

SUPE

ENG

OPE

SUPE

ENG

OPE

SUPE

ENG

OPE

SUPE

ENG

OVERRIDE SHUTDOWN ENABLE/DISABLE LOAD/DUMP CHANGE TIME OR DATA

F1 =CHECK F3 = SET OFFLINE F2 = INSTALL F4 = PRINT

F5 = ABORT

F9 = PACK NCF

CONSOLE DATA PAGE 6OF 11 ON-LINE PHYSICAL NODE COMMAND ACCESS TABLE

CHANGE AREA

OPER

SUPE

ENG

OVERRIDE CHANGE AREA

OPER

SUPE

ENG

CHANGE ALENBST

OPE

SUPE

ENG

IDLE PROCESS MANAGER

OPE

SUPE

ENG

DEMAND CHECKPOINT MODE

OPE

SUPE

ENG

ENABLE DISABLE AUTO CHECKPOINT

OPER

SUPE

ENG

OPE

SUPE

ENG

OPE

SUPE

ENG

OPE

SUPE

ENG

OPE

SUPE

ENG

OPE

SUPE

ENG

OPE

SUPE

ENG

SWITCH PRIMARY TO SECONDARY OVERRIDE SWITCH PRIMARY TO SECONDARY ENABLE/DISABLE HISTORY COLLECTION HOT/WARM/COLD/NO_PROCESS START AM SPARE F1 =CHECK F3 = SET OFFLINE F11 = TAB F2 = INSTALL F4 = PRINT

F5 = ABORT F9 = PACK NCF

FIG 9.7, 9.8 CONSOLE DATA PAGE 7 OF 11 ON-LINE

67

OPER

SUPE

ENG

OPER

SUPE

ENG

OPER OPER

SUPE

ENG

F11 = TAB

PHYSICAL MODE COMMAND ACCESS TABLE PRINTER ASSIGHMENT CHANGE CLEAR MAINTENANCE LOAD TEST LOAD INIT NO POINT PROCESS COMMAND LOAD OF PROCESS CATEWAY MODE HG/NIM COMMAND RESTORE OF PROCESS NETWORK DEVICE COMMAND LOAD OF PROCESS NETWORK DEVICE COMMAND CHECKPET OF PROCESS NETWORK DEVICES

F1 =CHECK F3 = SET OFFLINE F5 = ABORT NCF F11 = TAB F2 = INSTALL F4 = PRINT

F9 = PACK

FIG 9.9

Volume Configuration: – This defines the HM’s file/volume storage space space definition for continuous history, check pointing, alarms, messages, process or system changes is done here. A volume definition actually defines the partitioning data for the hard disk HISTORY MODULE PAIR SELECTION MENU 1 OF 1 ON-LINE MODE PAIR

PRIMARY 1 NODE 412

SECONDARY

NODE

DRIVES 1

PAGE

NO PAIR

NODE 1 NODE

NODE

SECONDARY

Drives

1

3

1

4

1

5

1

6

1

7

1

8

1

9

1

1

2

F3 = SET OFFLINE

PRIMARY

F5 = ABORT

F11 = TAB

FIG 9.10

68

F4 = PRINT

CHAPTER-9 COMPARISON OF DCS, PLC,PLC WITH SCADA DISTRIBUTED CONTROL SYSTEM: Definition : Functionally and physically separate automatic process controllers, process monitoring and data logging equipment connected with each other to share relevant information for optimal plant control is called a distributed control system. DCS system is superior in Communication. The advantages of DCS are 1. 2. 3. 4.

Superior in Communication. Redundancy is possible. Data security and availability Algorithms. Failure of one element of the control system may not effect the entire plant control. 5. Memory capacity high. 6. Mass storage facility historisation. 7. Functions are distributed. 8. EASE OF MAINTENANCE. 9. FUTURE EXPANSION SIMPLE. 10. Gate ways to various plc’s, computers, special purpose controllers, other systems etc APPLICATIONS OF DISTRIBUTED CONTROL SYSTEMS: 1.DCS Systems are employed in power plants for safe operation of boiler and turbine control and protection systems. 2.DCS Systems are employed in pharmaceutical industries for continuous and as well as batch processing. 3.DCS Systems are employed in cement plants for raw material handling, rotary kiln and cooler operations. 4.DCS Systems are employed in steel plants for blast furnace sequence of operation and for mini blast pre-heater controlling. 5.DCS systems are employed in Aluminum industries. 6.DCS Systems are employed in fertilizer industries. 7.DCS Systems are employed in refineries for emergency safety systems. 8.DCS Systems are employed for off shore fire& gas protection.

PROGRAMMABLE LOGIC CONTROLLER: Definition : A solid state control unit designed to automatically control machines and process it’s a digital electronic apartments with a programmable memory for strong instructions to implement specific functions such as logic servicing, timing counting and arithmetic to control machines and process. Advantages: 1. With standards rugged industrial environment such as temperature and humidity. 2. Easily installed and maintained 3. Reusable (i.e., can be moved and reprogrammed) 4. Modular (i.e., parts can be replaced easily for maintenance (or) repair) 5. Easy transition for people who worked with Relays SCADA: SCADA standards for supervisory control and data acquisition as the name indicates it is not a fully control system but rather focus on the supervisory level as such it is a purely software package i.e., positioned on top of hard ware to which is interface in general via PLC. FIX DMACS: Fully integrated control system distributed manufacturing automation and control software SCADA NODE: A scada node is one that has a data base and runs the I/O drives and SAC IPC I/O driver communicates with Honeywell 620 processors by interfacing to Honeywell intelligent, device interface modules and supported modules are : 1. IPC 620 communication interface modules (CIM) 2. IPC 620 data collection modules (DCM) The I/O drive implements Honeywell/IP’s asynchronous byte count (ABC) protocol True system redundancy DCS systems typically after the ability to operate with redundancy at every level true DCS systems require one time set up and make information available system wide without any additional configuration or effort. PLC system usually requires data movement and multiple HMI databases or at least some sort of OPC transfer to replace data across a connected system. This is case of PLC / HMI combination – not PLC / SCADA combination. First, PLC’s don’t have a terribly friendly user interface when it comes to loop control issues they are not supposed to.

CHAPTER-10 CASE STUDY DRUM LEVEL CONTROL: Water Cycle: The main purpose of most boilers is to heat water to steam. To accomplish this a series of tubes are placed in the boiler to confine the water and provide a large heat transfer surface for interfacing with the hot gases of combustion. The water in these tubes is turned to steam. A large heater is provided on each end of the tubes to distribute the water from Control: The object of the control system is to provide steam at a constant pressure, and to do so safely minimum cost. The control must be flexible enough to react to changes in the amount of steam required and provide steam at an optimum efficiency. The control must provide adequate feed water to exactly offset that drawn off as steam and last as blown down. At the same time the system has to provide adequate fuel to produce the heat needed to convert the water to steam an amount of to completely burn the fuel must be made available. And, off course, all these functions must be ordinate to provide not only maximum efficiency but also safety. The control scheme outs typical and includes sum of the important concepts. FEED WATER CONTROL We all look at the feed water portion of the control scheme. The aim of this part of the control is to maintain quite precisely the liquid level in the boiler drum to maximize the steam water separation maintaining the level is also important to assure that liquid is present in the boiler tubes. This assures the tubes will be cooled by the water as it boils and acts to protect them from over heating in addition, it assures that there will be the water circulation described pervasively the main elements of the control of the drum leveler the measurement of the liquid level in the drum and the control of the feed water flow valve. The obvious control would be to provide the drum level measurement to a level controller whose output regulate the feed water control valve (Single Element) this is not, however, a good solution here the primary reason this does not provide good control is that the level is a slow responding phenomenon that tends to integrate the results of the feed water flow in and steam out. That is a change in the feed water flow very long time to show up as a small increase in the level this is due to the large volume capacity of water in the boiler.

If the steam flow changes, this will affect the level, which in turn will control the feed water valve. As seen before, this is very slow and what we really want to do is to sense a change in steam flow and make a change to the feed water flow. We can do this by providing the steam flow measurement as a feed forward signal in the level controller in this way the feed forward signal from steam will effect the feed water valve for changes in steam flow while the level control accurately maintain the correct level by controlling the feed water to correct for losses and minor changes. This control system is called ” two element feed water control.” There is another phenomenon that happens in a boiler “shrink and swell” that we need to look at when there is a change in steam flow (consider an increased demand and resulting increase in steam flow) the pressure in the boiler and drum will immediately begin to be reduced as the steam is drawn off when these happens the vapor bubbles in the boiler will expand the displacing the water in the boiler which increases the liquid level in the drum calling for less feed water flow the level controller. This is off course, the wrong direction has the feed water flow should be increased to replace the increase the steam drawn off. When the cold feed water enters the drum it cools water in the boiler which condensates the steam bubbles which reduces the column and the reduces the drum level. Again the measurement going the wrong way that is, more liquid is resulting in the measurement indicating the lower level the shrink and swell phenomenon are transects from changes in steam flow and feed water and are relatively short lived. The phenomenon is over come by a Sophisticated scheme called the “three element drum level control system”. Here, feed water flow to the boiler is actually measured and controlled. The flow rate is based on a divine signal, which is the result of both the steam flow, and feed water signal is drum level controller. Now as steam flow increases feed water flow is increased and when flow is decreases less feed water flow is called for the drum level controller will maintain correct level by adjusting the feed water flow demand to correct for losses and minor changes

SINGLE ELEMENT CONTROL

TWO ELEMENT CONTROL

Steam flow DRUM LEVE L

DRUM LEVE L F T

L T

L T

PV sp

LIC

M/A

Lt :level transmitter

LIC

Ft :flow transmitter Ff :feed forward control m/a:manual/auto pv:process variable sp:set point

FF

M/A

Fig 11.1

feed water line control valve Fig 11.2

F T

M/A

L F LI T C

F

DRUM LEVE L

THREE ELEMENT CONTROL

Steam flow

DRUM LEVE L

F T L T Square root

Feed water flow

F T

Level transmitter pv

LIC

Level indicating control

pv

FF

sp LIC

M/A

Ft :flow transmitter Ff :feed forward control m/a:manual/auto pv:process variable sp:set point

feed water line control valve

fig 11.3

CHAPTER-11

RESULTS AND CONCLUSIONS 1.RESULTS: 1.In Command processor “FN” command is very useful to find the data bases where the point used in the entire DCS.When ever attending a point we are using the “FN” Command and keep the point in manual (or) force condition if required. We can attend the problem and after completion we will keep it normal. 2. During the study of my project one-day problem occurred in LM Processor, found system status LED is flickering at Universal Station and system alarms appeared in Alarm Summary. By going to Event History Menu of that particular Node observed that Program is not there in Primary processor and the secondary Processor has taken lead. And observed that all LED’S are not glowing in LM Processor rack. Checked LM Processor in coming supply 230 v ac is o.k. and checked fuse of power supply module and it is also o.k. ,and secondary is in running condition. Switched off the power supply to processor rack which was not running, changed the new power supply module and connected the communication cable to secondary processor which is in operation condition and down loaded the program from the lead processor to personal computer. The Communication cable connected the processor where there is no program to personal computer and uploaded the program from pc to processor. Now the Processor became healthy and all LED’s are glowing .Now swapped the Processor from Secondary to Primary and the system became healthy. 2.FUTURE SCOPE : Today Honeywell has raised the power of TDC3000 system to a new level to TDC3000X, and Experian which is server client under development stage. And the following are the changes implemented in TDC 3000X: 1. High Performance Manager. 2. Universal station X. 3. Plant Network Module. 4. Personal Computer Network Module. 5. Application Module. High Performance Manager:

The high performance process manager (HPM) represents an evolution of the advanced process manager. HPM control performance is significantly greater, with five times the processing power of APM . The HPM offers flexible I/O functions for both data monitoring and control. UNIVERSAL STATION ‘X: The Universal station’x is a Universal station that is augmented with an industry standard coprocessor. This serves two basic functions as a human interface to the process and as an interface to UNIX-based devices that exist on a user’s plant –wide communications network. The result is a station that, in addition to performing all functions of the standard US, assumes the functionality of a workstation operating under UNIX in the X window software environment. Plant Network Module : The PLNM provides an interface between the LCN and DEC VAX or Alpha AXP computers. Connections of computer systems makes it possible for computer-level functions to be integrated into the TPS system. The CM50S software package is available for use with the PLNM. It uses an Ethernet LAT communication channel between a VAX or Alpha AXP computers and up to 4 PLNM’s. Personal Computer Network Module: The PCNM consists of hardware and software that serves as a secure interface to multiple personal computers over an Ethernet or Token Ring Local Area Network. Users on the network have real-time access to LCN data for viewing in graphic displays, on spreadsheets, or in other third party applications. Application Module: The application module is used for point processing ,broad proportional integral derivative(PID) algorithm handling, and control language (CL).It can communicate with other modules on single or multiple LCN’s&with process connected devices on Universal Control Networks.

3. CONCLUSION

By doing this project, I got acquired knowledge regarding DCS. How the System is installed, and different nodes are addressed, and the type of communication between node to nodes, and different data points are build, and the types of algorithms used, and uses of Command Processor, Historisation, Area data base, Network configuration, APM configuration And LM configuration. During the study of my project I have observed that we are transferring house load logic from LM Processor LM 15 of UCN 01 to LM 15 of UCN02 by using digital output of LM 15 of UCN 01 as digital input at LM 15 of UCN02 through hardware cable .I have given suggestion to implement Application Module in our plant .By using Application Module any number of I/O’s can be transferred from one UCN to another UCN though logic point or control language through software with out using additional cabling .In addition Application Module offers a wider selection of data point scheduling intervals.