GE 90-30/20/Micro manual PID Parameter Block, PID Parameters Overview, Plc

4

PID Parameter Block:

Besides the 2 input words and the 3 Manual control contacts, the PID block uses 13 of the parameters in the RefArray. These parameters must be set before calling the block. The other parameters are used by the PLC and are non-configurable. The %Ref shown in the table below is the same RefArray Address at the bottom of the PID block. The number after the plus sign is the offset in the array. For example, if the RefArray starts at %R100, the %R113 will contain the Manual Command used to set the Control Variable and the integrator in Manual mode.

Table 4-4. PID Parameters Overview

Register	Parameter	Low Bit Units	Range of Values
%Ref+0000	Loop Number	Integer	0 to 255 (for user display only)
%Ref+0001	Algorithm	N/A; set and
		maintained by the	Non-configurable
		PLC
%Ref+0002	Sample Period	10 milliseconds	0 (every sweep) to 65535 (10.9 Min).
			Use at least 10 for 90-30 PLCs (see Note
			on page 4-171).
%Ref+0003	Dead Band +	PV Counts	0 to 32000 (never negative)
%Ref+0004	Dead Band —	PV Counts	–32000 to 0 (never positive)
%Ref+0005	Proportional Gain –Kp	0.01 CV%/PV%	0 to 327.67 %/%
%Ref+0006	Derivative Gain–Kd	0.01 seconds	0 to 327.67 sec
%Ref+0007	Integral Rate–Ki	Repeat/1000 Sec	0 to 32.767 repeat/sec
%Ref+0008	CV Bias/Output Offset	CV Counts	–32000 to 32000 (add to integrator
			output)
%Ref+0009	Upper Clamp	CV Counts	–32000 to 32000(>%Ref+10) output limit
%Ref+0010	Lower Clamp	CV Counts	–32000 to 32000(<%Ref+09) output limit
%Ref+0011	Minimum Slew Time	Second/Full	0 (none) to 32000 sec to move 32000 CV
		Travel
%Ref+0012	Config Word	Low 5 bits used	Bit 0 to 2 for Error+/–, OutPolarity,
			Deriv.
%Ref+0013	Manual Command	CV Counts	Tracks CV in Auto or Sets CV in Manual
%Ref+0014	Control Word	Maintained by the	PLC maintained unless set otherwise: low
		PLC, unless Bit 1	bit sets Override if 1 (see description in
		is set.	the “PID Parameters Details” table on
			page 4-174)
%Ref+0015	Internal SP	N/A; set and	Non-configurable
		maintained by the
		PLC
%Ref+0016	Internal CV	N/A; set and	Non-configurable
		maintained by the
		PLC
%Ref+0017	Internal PV	N/A; set and	Non-configurable
		maintained by the
		PLC
%Ref+0018	Output	N/A; set and	Non-configurable
		maintained by the
		PLC

GFK-0467K Chapter 4 Series 90-30/20/Micro Instructions Set 4-173