Mitsubishi Electric FR-F740 EC Instruction Manual page 450

Communication operation and setting
● Error response
An error response is returned if the query message received from the master has an illegal
function, address or data. No response is returned for a parity, CRC, overrun, framing or
busy error.
NOTE No response message is sent in the case of broadcast communication also.
Error response (Response message)
Slave Address
Message
Slave address
Function
Exception code
Tab. 6-84:
Code
01
02
03
Tab. 6-85:
An error will not occur in the following cases:
– Function code H03 (Read Holding Register Data )
When the No. of Points is 1 or more and there is one or more holding registers from which
data can be read.
– Function code H10 (Write Multiple Holding Register Data)
When the No. of Points is 1 or more and there is 1 or more holding registers to which
data can be written.
Namely, when the function code H03 or H10 is used to access multiple holding registers,
an error will not occur if a non-existing holding register or read disabled or write disabled
holding register is accessed.
NOTES An error will occur if all accessed holding registers do not exist.
Data read from a non-existing holding register is 0, and data written there is invalid.
6 - 300
H80 + Function
(8 bits)
Description of response data
Error Item
ILLEGAL FUNCTION
(Function code illegal)
ILLEGAL DATA
ADDRESS
(Address illegal)
ILLEGAL DATA VALUE
(Data illegal)
Error code list
Function Exception Code
(8 bits)
Description
Set the address received from the master.
The master-requested function code + H80 is set.
The code in the following table is set.
Description
The set function code in the query message from the master cannot be
handled by the slave.
The set register address in the query message from the master cannot be
handled by the inverter.
(No parameter, parameter read disabled, parameter write disabled)
The set data in the query message from the master cannot be handled by
the inverter.
(Out of parameter write range, mode specified, other error)
CRC Check
L
(8 bits)
(8 bits)
Parameter
H
(8 bits)