Pakscan IIS Technical Manual Issue 1.0
Publication S130E 79
12.8 Sequencer Information
The Pakscan IIS master station includes a powerful sequence control function that permits the user to produce
sequences for the automatic operation of the plant equipment. In addition every output can include an interlock
function to prevent plant mis-operation.
The construction of sequences requires the use of a special programme that operates on a standard PC. This
software, SCT, is described in its own manual.
To ensure correct communications when setting the SCT system to link to the master station the following
should be chosen.
Protocol: Generic Modbus
Baud rate: 9600 (unless the PC’s port is changed)
Parity: Odd
The following information defines the sequence and interlock capability.
Sequences: 80
Interlocks: 128
Sequence Control Blocks: 1000
Maximum number of blocks in one sequence: 100
Functions: 80
General Registers: 600
Sequence Flags: 1024
Timers: 128
PID loops: 16
Sequences 1 to 16 are executed in 0.25 sec, and all 80 sequences are executed in 1 second, so sequences
number 1 to 16 are executed 4 times a second. The PID loops are all executed in 0.25 seconds and 4 times a
second.
Data Base Locations:
The front panel LED’s and Function buttons are accessed as DO and DI points in the master station data base
when using them in a sequence. They are identified as follows:
Function Button
Identifier
LED
Identifier
F1
DI 00 01
L1
DO 00 01
F2
DI 00 02
L2
DO 00 02
F3
DI 00 03
L3
DO 00 03
F4
DI 00 04
L4
DO 00 04
F5
DI 00 05
L5
DO 00 05
F6
DI 00 06
L6
DO 00 06
F7
DI 00 07
L7
DO 00 07
F8
DI 00 08
L8
DO 00 08
