Instruction manual

8. TROUBLESHOOTING
IMR01H02-E3
81
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Modbus
Problem Probable cause Solution
No response Wrong connection , no connection or
disconnection of the communication cable
Confirm the connection method or
condition and connect correctly
Breakage, wrong wiring, or imperfect
contact of the communication cable
Confirm the wiring or connector and
repair or replace the wrong one
Mismatch of the setting data of
communication speed and data bit
configuration with those of the host
Confirm the settings and set them
correctly
Wrong address setting
A transmission error (overrun error,
framing error, parity error or CRC-16
error) is found in the query message
Re-transmit after time-out occurs or
verify communication program
The time interval between adjacent data in
the query message is too long, exceeding
24 bit’s time
Error code
1
Function cod error
(Specifying nonexistent function code)
Confirm the function code
Error code
2
When any address other than 0000H to
02EEH and 1388H to 14A0H are specified
(However, no error returns for any address
from 03E8H to 0563H. Therefore, do not
access any of the above addresses.)
Confirm the address of holding register
Error code
3
When the specified number of data items
in the query message exceeds the
maximum number of data items available
Confirm the setting data
Error code
4
Self-diagnostic error Turn off the power to the instrument. If
the same error occurs when the power is
turned back on, please contact RKC
sales office or the agent.