Omron C200HX Operation Manual page 291

Special Math Instructions
DM
Parameters
PV: word
PID control
IR 010
Manipulated variable output:
IR 020
Input Values and
Manipulated Variable
Ranges
The PID constants used in PID calculations will not be changed if the proportion-
al band (P), integral constant (Tik), or derivative constant is changed after
IR 00000 turns ON.
C: DM 0200 012C Set value: 300
C+1: DM 0201 0100 Proportional band: 10.0%
Integral time: 120.0 s
C+2: DM 0202 1200
C+3: DM 0203 0400 Derivative time: 40.0 s
C+4: DM 0204 0005 Sampling period: 0.5 s
C+5: DM 0205 0000
C+6: DM 0206 0888
C+7: DM 0207
Work area
to
C+32: DM 0232
Note When IR 00000 is OFF, operation can be the same as
manual operation by writing to IR 020.
The number of valid input data bits for the measured value is designated by the
input range setting in C+6, bits 08 to 11, and the number of valid output data bits
for the manipulated variable output is designated by the output range setting in
C+6, bits 0 to 3. These ranges are shown in the following table.
C+6, bits 08 to 11 or
C+6, bits 00 to 03
0
1
2
3
4
5
6
7
8
If the range of data handled by an Analog Input Unit or Analog Output Unit can-
not be set accurately by setting the number of valid bits, APR(069) (ARITH-
METIC PROCESS) can be used to convert to the proper ranges before and after
PID(190).
The following program section shows an example for a DRT1-AD04 Analog In-
put Unit and DRT1-DA02 Analog Output Unit operating as DeviceNet slaves.
The data ranges for these two Units is 0000 to 1770 Hex, which cannot be speci-
fied merely by setting the valid number of digits. APR(069) is thus used to con-
vert the 0000 to 1770 Hex range of the Analog Input Unit to 0000 to FFFF Hex for
input to PID(190) and then the manipulated variable output from PID(190) is
Reverse operation (bit 00: 0)
2-PID parameter = 0.65 (bits 04 to 15: 000 hex)
Manipulated variable output range: 16 bits (bits 00 to 03: 8 hex)
Integral/derivative constant: time designation, 100-ms units (bits
04 to 07: 8 hex)
Input range: 12 bits (bits 08 to 11: 8 hex)
Number of valid bits
8 0000 to 00FF Hex
9 0000 to 01FF Hex
10 0000 to 03FF Hex
11 0000 to 07FF Hex
12 0000 to 0FFF Hex
13 0000 to 1FFF Hex
14 0000 to 3FFF Hex
15 0000 to 7FFF Hex
16 0000 to FFFF Hex
Section 5-21
Range
273