Pid Deviation Reverse Output; Pid Variable Range Limit - Omron RX Series User Manual

PID Deviation Reverse Output

Depending on the system configuration, sensor characteristics, etc., the polarity of deviation between
the target and feedback values may not match the inverter's command. In this case, you can invert the
deviation polarity by setting the PID Deviation Reverse Output (A077) to 01.
(Example)
To control a refrigerator compressor
If you are using a temperature sensor designed for use in a temperature range of 0 to 100°C at 0 to
10 V and the target and current temperatures are 5°C and 10°C, respectively, the inverter attempts to
reduce the frequency under normal PID control since the feedback value is larger than the target value.
In this case, set A077 to 01. Then, the inverter attempts to increase the frequency.
PID target
value

PID Variable Range Limit

• This function limits the PID output to within the variable range defined based on the target value.
• To use this function, set the PID Variable Range Limit (A078) with the maximum frequency defined as
100%. Then, the output frequency will be limited to within a range of "Target value ±A078."
• This function is disabled when A078 is set to 0.0.
PID output [%]
PID target
value
PID Reverse Output
• Under normal PID control, the frequency reference to the inverter will be limited to 0 Hz if the result of
PID operation is a negative value. However, when the PID Selection (A071) is set to 02 (Reverse
output enabled), reverse output is enabled for the inverter if the result of PID operation is a negative
value.
• When A071 is set to 02, the PID Variable Range Limit (A078) and the PID disabled function allocated
to any multi-function input terminal are disabled.
High-function General-purpose Inverter 3G3RX-V1 User's Manual (I578-E1)
A077
–1
PID feedback value
PID calculation
PID output range
PID variable range (A078)
PID variable range (A078)
Time
7 Detailed Functions
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