Hitachi SJ700D-004L, Instruction Manual

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Chapter 4 Explanation of Functions
4-132
(Vii) Response upon error
Field configuration
Slave address
Function code
Exception code
CRC-16
If the query includes an error (other than a communication error), the inverter returns an exception response
without executing the function specified by the query.
To know the error, check the function code set in the exception response. The exception response in reply to a
query includes a function code that is the sum of "80h" and the function code specified by the query.
The exception code in the exception response indicates the content of the error.
Refer to “(3) Explanation of function codes / (ix) Exception response” for more information.
(iv) No response
The inverter ignores a query without returning any response if:
- the query is a broadcast query (slave address setting is 0),
- a communication occurs during the reception of the query,
- the slave address specified in the query differs from that of the inverter,
- the time interval between data items in the query message is less than the time corresponding to the
transmission of 3.5 characters,
- the data length of the query is invalid,
- recieving interval in the frame is more than the time corresponding to the transmission of 1.5 characters,
- query’s error checking code is wrong (CRC error) or
- the query is a group broadcast query (slave address setting is 250 to 254).
Note: In the master system, set a timer to monitor the responses from the inverter, and configure the master system
so that, when the inverter does not return the response to a query within a specified limit time, the master
system resends the query.