Mitsubishi Electric FR-F820-00046 Instruction Manual page 506

NOTE
• No response is also returned in the case of broadcast communication.
• Error response (Response message)
a. Slave address b. Function
H80 + Function
(8 bits)
(8 bits)
Message
a Slave address
b Function
c Exception code
• Error code list
Code Error item
01 ILLEGAL FUNCTION
02
ILLEGAL DATA ADDRESS
03 ILLEGAL DATA VALUE
*1 An error response is not returned in the following cases:
(a) Function code H03 (reading data of holding registers)
When the number of registers is specified as one or more and there are one or more holding registers from which data can be read
(b) Function code H10 (writing data to multiple holding registers)
When the number of registers is specified as one or more and there are one 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 response is not returned even if a
nonexistent holding register or holding register that cannot be read or written from/to is accessed.
NOTE
• An error response is returned if none of the accessed holding registers exist. When an accessed holding register does not
exist, the read value is 0 and the written data is invalid.
• Error detection of message data
The following errors are detected in message data from the master. The inverter output is not shut off 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.
 MODBUS register
• The following shows the MODBUS registers for system environment variables (read/write), real time monitor items (read),
parameters (read/write), fault history data (read/write), and model information monitor items (read).
c. Exception code
L
(8 bits)
(8 bits)
Set the address received from the master.
The function code requested by the master and H80 is set.
The codes in the following table are set.
The query message from the master has a function code that cannot be handled by the slave.
The query message from the master has a register address that cannot be handled by the slave.
*1
(No parameter, parameter cannot be read, parameter cannot be written)
The query message from the master has data that cannot be handled by the slave.
(Out of parameter write range, a mode is specified, or 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
H
(8 bits)
Description
Error description
When this error occurs, Pr.343 is
incremented by one.
When this error occurs, the LF signal is
output.
5.12 (N) Communication operation parameters
Inverter operation
5. PARAMETERS
1
2
3
4
5
6
7
8
9
10
505