Hitachi SJ7002 Series Instruction Manual page 306

Message
Configuration:
Response
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Header and trailer (silent interval):
Latency is the time between the reception of a query from the master and transmission of a
response from the inverter.
• The header and trailer set the total time the inverter should wait before sending a response
after having received a query from the master system.
• Be sure to specify the time corresponding to the transmission of 3.5 characters (24 bits) as
the waiting time. If a shorter waiting time (corresponding to the transmission of fewer than
3.5 characters) is specified, the inverter will not respond.
• The actual waiting time is the sum of the silent interval (corresponding to the transmission of
3.5 characters) and the communication wait time (C078).
Time required for communication:
• After the inverter receives a query, the inverter waits for the sum of the silent interval (corre-
sponding to the transmission of 3.5 characters) and the communication wait time (C078)
before sending a response.
• After receiving a response from the inverter, the master system must wait for the silent
interval (corresponding to the transmission of 3.5 characters) or longer before sending the
next query to the inverter.
Normal response:
• If the query specifies the function code (08h) for the loopback test, the inverter returns a
response that has the same contents as the query.
• If the query specifies a function code (05h, 06h, 0Fh, or 10h) for writing data to registers or
coils, the inverter returns the query without a change as a response.
• If the query specifies a function code (01h or 03h) for reading a register or coil, the inverter
returns a response that contains the slave address and function code specified in the query
and the data read from the register or coil.
Response when an error occurs:
• When finding any error in a query (except for a transmission error), the inverter returns an
exception response without executing anything,
• You can check the error by the function code in the response. The function code of the
exception response is the sum of the function code of the query and 80h.
• The content of the error is known from the exception code.
Field Configuration
Slave address
Function code
Exception code
CRC–16
Exception Code
0 1 h The specified function is not supported.
0 2 h The specified address is not found.
0 3 h The format of the specified data is not acceptable.
2 1 h The data to be written in a holding register is outside the inverter.
SJ700 Inverter
2
Description
B–23