Mitsubishi FX3U Series User Manual page 111

FX Series Programmable Controllers
3U
User's Manual - MODBUS Serial Communication Edition
MODBUS
Error
Code
Bit-level Error
0204
Parity, overrun (rx register) or framing error
CRC/LRC Error
0205 Message CRC/LRC is invalid, or message
length ≤ 3 characters (RTU) or ≤ 8 characters
(ASCII)
Bus Character Overrun
- When more than 256 bytes are
received in RTU mode (more than 513
0206
bytes in ASCII mode)
- (Slave only) When another telegram is
received while the former request is still
in process
Data Length Mismatch
The received data does not match the byte
0207
count value within the telegram, or the device
count exceeds the maximum limit for the
command.
Unconvertible Character Error
0208 When in ASCII mode a byte code can not be
converted
(any character except '0'-'9' and 'A'-'F' ('a'-'f'))
Unsupported Command Code Error
0209
The requested Command Code is invalid or
not supported
Error Name and Details
12.6 MODBUS Error Code List
Master
Related Devices:(M & D)
/ Slave
Master
See above
/ Slave
Master
See above
/ Slave
Master
See above
/ Slave
Master
See above
/ Slave
Master
See above
/ Slave
Slave See above
12 Troubleshooting
11
Corrective Action
Check
Communication
12
Format data register
D8400 or D8420 for
errors.
Check the
Communication
Format, Turn Around
Delay, and Message
to Message Delay
data registers for
errors;
D8400 and
D8410-D8411, or
D8420 and
D8430-D8431.
Check the Turn
Around Delay and
Message to Message
Delay data registers
for errors;
D8410-D8411, or
D8430-D8431.
Also verify that the
serial port settings
are correct.
Verify that the Slave
is using MODBUS
Serial
Communication and
that the correct
command was
received.
Also verify that the
device count of the
command is within
the limits of the Slave
and Master.
Protocol error may
occur if you don't
program correctly.
See Corrective
Actions for Error
Code 207.
Verify that the
command used is
within the Master and
Slave specifications.
107