Omron CS1G/H-CPUxxH Instructions Manual page 714

Data Control Instructions
Note
Example 1:
Interrupting PID Control to
Perform Autotuning
000000
PIDAT
S 0010
C
D00200
D 0020
W00000
SETB
D00209
#000F
Parameters
PV:
PID calculation
CIO 0010
MV output: CIO 0020
1. When the unit is designated as 1, the range is from 1 to 8,191 times the
period. When the unit is designated as 9, the range is from 0.1 to 819.1 s.
When 9 is designated, set the integral and derivative times to within a
range of 1 to 8,191 times the sampling period.
2. Setting the 2-PID parameter ( α ) to 000 yields 0.65, the normal value.
When the manipulated variable output limit control is enabled (i.e., set to
"1"), set the values as follows:
0000 ≤ MV output lower limit ≤ MV output upper limit ≤ Max. value of output range
At the rising edge of CIO 000000 (OFF to ON), the work area in D00211 to
D00240 is initialized according to the parameters (shown below) set in
D00200 to D00208. After the work area has been initialized, PID control is
executed and the manipulated variable is output to CIO 0020.
While CIO 000000 is ON, PID control is executed at the sampling period
intervals according to the parameters set in D00200 to D00210. The manipu-
lated variable is output to CIO 0020.
The PID constants used in PID calculations will not be changed even if the
proportional band (P), integral constant (Tik), or derivative constant is
changed after CIO 000000 turns ON.
At the rising edge of W 000000 (OFF to ON), SETB(532) turns ON bit 15 of
D00209 (C+9) and starts autotuning. When autotuning is completed, the cal-
culated P, I, and D constants are written to C+1, C+2, and C+3. PID control is
then restarted with the new PID constants.
C: D00200
0 1 2 C
C+1: D00201
0 0 6 4
C+2: D00202
0 4 B 0
C+3: D00203
0 1 9 0
C+4: D00204
0 0 3 2
C+5: D00205
0 0 0 8
C+6: D00206
0 4 9 4
C+7: D00207
0 0 0 0
C+8: D00208
0 0 0 0
C+9: D00209
0 0 0 0
C+10: D00210
0 0 0 0
C+11: D00211
to Work area
C+40: D00240
Set value: 300
Proportional band: 10.0%
Integral time: 120.0 s
Derivative time: 40.0 s
Sampling
Reverse operation (bit 00: 0), PID constant change enable setting =
period: 0.5 s
OFF (bit 01: 0), set value = manipulated variable output 50% (bit
03: 1), 2-PID parameter = 0.65 (bits 04 to 15: 000 hex)
Manipulated variable output range: 12 bits (bits 00 to 03: 4 hex),
Integral/derivative constant: time designation (bits 04 to 07: 9 hex)
Input range: 12 bits (bits 08 to 11: 4 hex),
Manipulated variable output limit control disabled (bit 12: 0)
AT Command Bit OFF (bit 15: 0),
AT Calculation Gain = 1.00 (bits 00 to 11: 000 hex)
Limit-cycle Hysteresis = 0.20%
Section 3-18
693