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52
SE
CTION 5
T
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F250
Setup Manual
SECTION 5
Troubleshooting and Maintenance
Serial Interface (RS-232C/RS-422) Errors
Problem
Probable cause
Reference
No communications are
possible.
•
The cables are not correctly wired.
•
The Controller's communications specifications do not
match those of the external device.
•
The communications mode was not selected under
[System settings/Communication/Serial].
Select [Normal], [Host link], or [Menu] in the
Communications (Serial) menu.
The status of communications can be checked with the I/O
monitor.
Operation
Manual
The Unit operates well
initially, but after a while
there is no response from
the Controller.
•
The reception buffer on the external device (e.g.,
computer) is full.
Check that settings allow the data to be properly received.
–
Cannot perform menu
operations from the
computer.
•
The communications mode was not set to Menu in the
[System settings/Communication/Serial].
Operation
Manual
Data cannot be saved.
•
The Controller's communications specifications do not
match those of the external device.
•
The flow control is turned OFF under [System settings/
Communication/Normal].
Operation
Manual