Common Communication Faults - Hitachi S1 Series Basic Manual

S1 series standard inverter

9.5 Common communication faults

Common communication faults include the following:
•
No response is returned.
•
The inverter returns an exception response.
Possible causes of no response include the following:
•
The serial port is set incorrectly. For example, the converter uses the serial port COM1, but
COM2 is selected for the communication.
•
The settings of the baud rates, data bits, end bits, and check bits are inconsistent with those set
on the inverter.
•
The positive pole (+) and negative pole (-) of the RS485 bus are connected reversely.
•
The resistor connected to 485 terminals on the terminal block of the inverter is set incorrectl
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