Programless Communications Errors - Omron EJ1 User Manual

Programless Communications
5-1-6

Programless Communications Errors

Possible Causes of
Parameter Access
Problems
Errors in
Communications with
PLCs
1,2,3...
Note
• A value outside the setting range was written.
• A non-existent Unit was accessed.
• An attempt was made to change a setting for which changes are prohib-
ited. Example: An attempt was made to change the SP during autotuning.
In the above cases, the Response Bits will be set to the following error values.
Bits
Read Response Bits
Setting Change Response Bits
Operation Command Response Bits
If an error value is set for Response Bits, check the following items.
• Setting range
• Unit number
• Whether or not the value being changed can be changed.
If noise or other cause results in a communications error with the PLC, the
EJ1 will stop programless communications and set the Operation Command
Response Bits to EEEE.
Method for Canceling Communications Errors
1. Set the Operation Command Request Bits to FFFF.
2. The Operation Command Response Bits will be set to FFFF and the pro-
gramless communications will return to the initial status.
Note If the Read Request Bits or Setting Change Request Bits are set,
restart operation according to the request.
3. Set the Operation Command Request Bits to 0000, then check that the Op-
eration Command Response Bits have been set to 0000.
Note Operation commands cannot be executed while the Operation
Command Response Bits are set to FFFF.
If the communications line is disconnected or the PLC power supply turns
OFF during programless communications, a programless communications
error will occur after the following times have expired.
Programless
communications
protocol
1:N NT Link
MC Protocol (Format 5) Programless Communications Receive Wait Times × 3 (6 s
If a programless communications error occurs because the PLC power supply
turns OFF when using the 1:N NT Link protocol, the error can be cleared by
turn ON the PLC power supply.
Operation
Single Read
Multi Read
Single Action
Multi action
Single Operation Commands
Multi Operation Commands
Maximum time until programless communications
30 s (See note.)
for the default setting)
Section 5-1
Error value
8001
8002
8001
8002
8001
8002
error
137