5.3 Description of Function Codes 5.3.8 J codes (Applied functions)
[ 4 ] PID command via communications link (J02 = 4)
Use function code S13 to specify the PID command by communications. The transmission data of 20000d (decimal)
is equal to 100% (maximum set point value) of the PID command. For details of the communications format, refer
to the RS-485 Communication User’s Manual.
• Other than the remote command selection by J02, the PID multistep commands 1, 2 or 3 (specified by
J136, J137 or J138, respectively) selected by the PID multistep commands “PID-SS1” and “PID-SS2”
can also be used as preset set point values for the PID command.
• In dancer control (J01 = 3), the setting command from the keypad is in conjunction with the function
code J57 (PID control: Dancer position set point), and it is saved as function code data.
Selecting feedback terminals
For feedback control, determine the connection terminal according to the type of the sensor output.
• If the sensor is a current output type, use the current input terminal [C1] (C1 function) of the inverter.
• If the sensor is a voltage output type, use inverter voltage input terminal [12], [V2], or [C1] (V3 function).
For details, refer to the descriptions of E61 to E63.
<Application example: Process control> (for air conditioners, fans and pumps)
The operating range for PID process control is internally controlled as 0% through 100 %. For the given feedback
input, determine the operating range to be controlled by means of gain adjustment.
Example: When the external sensor has the output range of 1 to 5 V:
• Use terminal [12] as the input terminal in voltage.
• Set the gain (C32 for analog input adjustment) to 200 % in order to make 5 V of the maximum output of the
external sensor to be 100% of input scale. For the input specification of terminal [12], 0-10 V is equivalent to 0-
100%. Therefore the gain has to be set 200 % (= 10 V / 5 V *100). Note also that any bias setting does not apply
to feedback control.
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