Pid Control Block Layout - Allen-Bradley SLC 500 Series Reference Manual

PID Control Block Layout

Table 9.2 Control Block Structure
15 14
Word 0 EN (1)
RA
Word 1 PID Sub Error Code (MSbyte)
Word 2 Setpoint SP
Word 3 Gain K
c
Word 4 Reset T
i
Word 5 Rate T
d
Word 6 Feed Forward/Bias
Word 7 Setpoint Max (SMax)
Word 8 Setpoint Min (SMin)
Word 9 Deadband
Word 10 Internal Use Do Not Change
Word 11 Output Max
Word 12 Output Min
Word 13 Loop Update
Word 14 Scaled Process Variable
Word 15 Scaled Error SE
Word 16 Output CV% (0 to 100%)
Word 17 MSW Integral Sum
Word 18 LSW Integral Sum
Word 19 Internal Use Do Not Change
Word 20 Internal Use Do Not Change
Word 21 Internal Use Do Not Change
Word 22 Internal Use Do Not Change
(1)
Applies to SLC 5/03 and higher processors with OS Series C FRN 11 and higher firmware.
(2)
Applies to the SLC 5/03 and higher processors.
(3)
You may alter the state of these values with your ladder program.
The control block length is fixed at 23 words and should be programmed as an
integer file. PID instruction flags (word 0) and other parameters are listed in
the following table.
13 12 11 10 09
DN PV SP LL UL
ATTENTION
Proportional Integral Derivative Instruction
08 07 06 05
DB (2) TF SC
DA
Do not alter the state of any PID control block value unless
you fully understand its function and related effect on your
process.
Publication 1747-RM001G-EN-P - November 2008
04 03 02 01
(2) (3) (3) (3)
RG OL CM AM
9-5
00
(3)
TM