Panasonic FP0H User Manual page 77

 Flag operations
Name Description
Turns ON when the [S1] control data value is outside the specified range.
Turns ON when the COM port specification of control data specified in [S1] is not MODBUS mode.
R9007
Turns ON when the number of send data [n] is 0.
R9008
Turns ON when the number of send data is negative.
(ER)
Turns ON when the number of send data [n] exceeds the operation memory area specified in [S2].
Turns ON when the number of send data [n] exceeds limitation in MODBUS specification.
8.2 Communication Instruction
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