Mitsubishi Electric FR-A800, Instruction Manual

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(N) Operation via communication and its settings Parameters
5 - 640
Error response
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An error response is returned if the query message received from the master contains an illegal
function, address or data.
No response is returned for parity, CRC, overrun, framing, and Busy errors.
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Error response (Response message)
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Error code list
An error does not occur in the following cases:
–
Function code H03 (read data of holding register)
When there are 1 or more number of reads (No. of Points) and there is 1 or more holding
register from where data can be read
– Function code H10 (write data to multiple holding registers)
When there are 1 or more number of writes (No. of Points) and there is 1 or more
holding registers to which data can be written.
In other words, when function code H03 or H10 is used and multiple holding registers are accessed,
an error will not occur even if a non-existent holding register or holding register that cannot be
read or written is accessed.
NOTE No response is also returned in the case of broadcast communication.
Slave Address Function Exception Code CRC Check
(8 bits)
H80 + Function
(8 bits)
(8 bits)
L
(8 bits)
H
(8 bits)
Message Description
Slave Address Set the address received from the master.
Function The function code requested by the H80 is set.
Exception Code The codes in the following table are set.
Tab. 5-290: Description of response data
Code Error Item Error description
01 ILLEGAL FUNCTION
The query message from the master is set with a function code that cannot
be handled by the slave.
02
ILLEGAL DATA ADDRESS
The query message from the master is set with a register address that
cannot be handled by the inverter.
(No parameter, parameter cannot be read, parameter cannot be written)
03 ILLEGAL DATA VALUE
The query message from the master is set with data that cannot be
handled by the inverter.
(Out of parameter write range, a mode is specified, other error)
Tab. 5-291: Error code list
NOTE An error will occur if all accesses holding registers do not exist. The data read value of non-existent
holding registers is 0, and data is invalid when written to non-existent holding registers.