Omron SYSMAC CP Series Instruction & Reference Manual page 310

2 Instructions
Precautions
When using TPO(685) in combination with PIDAT(191) in a cyclic task and also using an interrupt
task, temporarily disable interrupts by executing DI(693) (DISABLE INTERRUPTS) ahead PIDAT(191)
and TPO(685). If interrupts are not disabled and an interrupt occurs between the PIDAT(191) and
TPO(685), the control period may be shifted.
Cyclic task
Sample program
Combining TPO(685) with PIDAT(191)
When CIO 0.00 is ON, TPO(685) takes the manipulated variable output from PIDAT(191) (contained in
D0), calculates the duty ratio from that manipulated variable value (Duty ratio = MV ÷ MV range), con-
verts the duty ratio to a time-proportional output, and outputs the pulses to bit 01 of CIO 100.
In this case, CIO 100 is allocated to a Transistor Output Unit and bit CIO 100.01 is connected to a solid
state relay for heater control.
0.00
2-274
DI
PIDAT
PV input
S
C PID parameters
Reception prohibited
Manipulated
D
variable
TPO
Manipulated
S
variable
Parameters
C
Pulse output
R
EI
Reception allowed
PIDAT
10
S PV input
C D200
PID parameters
D D0
Manipulated variable
TPO
Manipulated variable
S D0
Parameters
C D500
R Pulse output
100.01
D200 Set value (SV)
D201 Proportional band (P)
:
D206
:
:
D500
1
Interrupt task
Interrupt task
When CIO 0.00 goes from OFF to ON, PID(190)
reads the parameters, performs the PID
calculation with the PV input in CIO 10, and
outputs the manipulated variable (MV) to D0.
TPO(685) calculates the duty ratio by dividing
the MV in D0 by the MV range (0FFF Hex since
the range is set to 12 bits), converts that duty
ratio to a time-proportional output, and outputs
the pulse output to bit 01 of CIO 100.
4
Output range: 4 hex
(12 bits: 0000 to 0FFF hex)
4
MV range: 4 hex
(12 bits: 0000 to 0FFF hex)
Input type: 1 hex (MV)
CP1E CPU Unit Instructions Reference Manual(W483)