Omron SYSDRIVE MX2 SERIES - Page 192

5-77
5-6 Operation Functions
SYSDRIVE MX2 Series USER'S MANUAL (3G3MX2-Axxxx)
5
Functions
PID Deviation Reverse Output
Depending on the sensor characteristics, etc. the polarity of deviation between the target value
feedback values may not match the Inverter's command. In this case, the deviation polarity can
be reversed by using the PID Deviation Reverse Output (A077 = 01).
Example) Controlling a refrigerator compressor
The temperature sensor specification is 0 to 100°C: 0 to 10 (V) and the target value
is 5°C.
If the current temperature is 10°C, "(Feedback value) > (Target value)" is satisfied
and therefore the Inverter frequency drops under normal PID control.
→ Set A077 to "01" so that the Inverter increases the frequency.
PID Variable Range Limit
This function limits PID output within a variable range relative to the target value.
To use this function, set PID Variable Range Limit (A078). The output frequency is limited
within a range of "target value ± (A078)", with the maximum frequency defined as 100%.
With A078 set to 0.0, this function is disabled.
PID Reverse Output
If the PID operation result is a negative value under normal PID control, the frequency
reference given to the Inverter is limited by 0 Hz. When PID Selection (A071) is set to "02:
Reverse output enabled," a reverse output can be output to the Inverter even when the PID
operation result is a negative value.
If A071 = 02: Reverse output enabled, PID Variable Range Limit (A078) explained above is
disabled.
PID target
value
PID feedback
PID operation
A077
−
1
PID output (%)
PID target value
PID output range
PID Variable Range Limit (A078)
Time (s)
PID Variable Range Limit (A078)