Omron NJ501-1500

2-413
2 Instruction Descriptions
NJ-series Instructions Reference Manual (W502)
Conversion Instructions
2
PIDAT
Temperature control is performed according to the following specifications.
The following setting is used for the CJ1W-PH41U Analog Input Unit.
The following I/O map settings are used.
• The manipulation value MV of the PIDAT instruction is obtained to control the output to the tempera-
ture controller. The output to the temperature controller is turned ON and OFF.
• The sampling period (InitSetParams.SampTime) of the PIDAT instruction is set to 100 ms. The task
period must be sufficiently shorter than 100 ms. Therefore, the value of MV is refreshed every 100
ms.
• The output control period is 1 s. During that period, the ON time and OFF time of the output control
value are controlled with a time-proportional output. For example, if the obtained value of MV is 20%,
the output to the temperature control is ON for 200 ms and OFF for 800 ms. This is repeated at a 1-s
period.
• If the most recent value of MV is smaller than the value of MV when the output control values were
determined, the output control values do not change. If the most recent value of MV is larger than the
value of MV when the output control values were determined, the most recent value is immediately
reflected in the output control values. For example, assume that the output control values were deter-
mined when the value of MV was 20% (ON 200 ms, OFF 800 ms). If after 100 ms, the new value of
MV is 30%, the output control values are immediately changed to turn the output ON for 300 ms and
OFF for 700 ms.
Specifications
Item Specification
Input type K thermocouple
Input Unit CJ1W-PH41U Analog Input Unit with Universal Inputs
Output Unit CJ1W-OD212 Transistor Output Unit
Set point 90°C
Sampling period for PID control 100 ms
Output control period 1 s
Configuration and Settings
Setting Set value
Input1:Input signal type K(1)
Unit I/O port Description Variable
CJ1W-PH41U Ch1_AIInPV Measurement value for input 1 (INT data) AI1
CJ1W-OD212 Ch1_Out00 Bit 00 of output word 1 DO1
Processing
200 ms 800 ms
PID processing
100-ms period
1-s period
Output control value
Time
MV at this point: 20% MV at this point: 30%
ON
OFF
300 ms 700 ms