Mitsubishi Electric 800 Series Instruction Manual page 511

 Error response
• 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.
NOTE
• No response is also returned in the case of broadcast communication.
• Error response (Response message)
a. Slave Address
(8 bits) H80 + Function
(8 bits)
Message
a Slave Address
b Function
c Exception Code
• Error code list
Code
01 ILLEGAL FUNCTION
02
ILLEGAL DATA ADDRESS
03 ILLEGAL DATA VALUE
*1 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 registers) 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
• 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.
• Error detection of message data
The following errors are detected in message data from the master. The inverter is not tripped even if an error is detected.
Error check items
Error item
Parity error
Framing error
Overrun error
Message frame error
CRC check error
NOTE
• The LF signal can be assigned to an output terminal by setting Pr.190 to Pr.196 (Output terminal function selection).
Changing the terminal assignment may affect other functions. Set parameters after confirming the function of each
terminal.
510
5. PARAMETERS
5.12 (N) Operation via communication and its settings
b. Function c. Exception Code
(8 bits)
Set the address received from the master.
The function code requested by the master + H80 is set.
The codes in the following table are set.
Error Item
The query message from the master is set with a function code that cannot be
handled by the slave.
The query message from the master is set with a register address that cannot
*1
be handled by the inverter.
(No parameter, parameter cannot be read, parameter cannot be written)
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)
Error description
The data received by the inverter is different from the
specified parity (Pr.334 setting).
The data received by the inverter is different from the
stop bit length (Pr.333/Pr.334) setting.
The next data has been sent by the master before the
inverter completes receiving the preceding data.
The data length of the message frame is checked,
and an error is generated if the received data length
is less than 4 bytes.
An error is generated if the data in the message frame
does not match the calculation result.
CRC Check
L H
(8 bits) (8 bits)
Description
Error description
Inverter operation
When this error occurs, Pr.343 is
incremented by one.
When this error occurs, the LF signal is
output.