Omron CP - PROGRAMMING MANUAL 05-2007 Programming Manual page 684

Data Control Instructions
Example
0.00
Note
Example 1: Combining TPO(685) with PID(190)
When CIO 0.00 is ON, TPO(685) takes the manipulated variable output from
PID(190) (contained in D0), calculates the duty ratio from that manipulated
variable value (Duty ratio = MV
proportional output, and outputs the pulses to CIO 100.05.
In this case, CIO 100 is allocated to a Transistor Output Unit and bit
CIO 100.05 is connected to a solid state relay for heater control.
PID
S 1000
PV input
C D200
PID parameters
D D0
Manipulated variable
TPO
S D0
Manipulated variable
C D5000
Parameters
R 100.05
Pulse output
D200 Set value (SV)
D201 Proportional band (P)
:
D206
:
:
D5000
1
When using TPO(685) in combination with PID(190) in a cyclic task and also
using an interrupt task, temporarily disable interrupts by executing DI(693)
(DISABLE INTERRUPTS) ahead PID(190) and TPO(685). If interrupts are not
disabled and an interrupt occurs between the PID(190) and TPO(685), the
control period may be shifted.
Cyclic task
MV range), converts the duty ratio to a time-
When CIO 0.00 goes from OFF to ON, PID(190)
reads the parameters, performs the PID calculation
with the PV input in CIO 1000, 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 CIO 100.05.
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)
DI
PID
S PV input
C
PID parameters Reception prohibited
Manipulated
D
variable
TPO
Manipulated
S
variable
C
Parameters
R
Pulse output
EI
Reception allowed
Section 3-17
Interrupt task
Interrupt task
651