Omron EJ1 User Manual page 231

Determining Errors from Indicators
Status
ERR Red, flashing
ALM Red, lit
HFU
Status
ALM Red, lit
206
Possible causes
There is an input error or a
remote SP input error.
An error has occurred for which
the Operation During Error
(Selection B) parameter is set to
MV at PV Error or Stop control.
An error has occurred in commu-
nications with a connected
G3ZA.
One of the following alarms has
occurred: heater burnout alarm,
heater short alarm, or heater
overcurrent alarm.
Possible causes
The power supply to the PLC
was interrupted after communi-
cations were established
between the PLC and EJ1.
The communications cable was
broken after communications
were established between the
PLC and EJ1.
Parameters for a Unit that does
not exist were registered in the
Programless Upload Settings or
Programless Download Settings
of the HFU.
An error has occurred in pro-
gramless communications.
An illegal operation command
code was written to the program-
less download area in the PLC.
Countermeasure
Check the wiring for the input or remote SP
input to be sure it is wired correctly, not broken,
and not shorted. Also check the input type.
Read status to determine the nature of the error
and take appropriate measures.
Check the connection to the G3ZA and take
appropriate measures.
Read the Error Channel A Status, the Channel
Status, and the Channel Alarm Status to deter-
mine the channel with the alarm and the nature
of the alarm, and take appropriate measures.
Countermeasure
Supply power to the PLC.
If the Operation Command Response Bits in the
Programless Upload Area set in PLC memory
are EEEE, write FFFF to the Operation Com-
mand Request Bits to restart communications.
Connect the cable.
If the Operation Command Response Bits in the
Programless Upload Area set in PLC memory
are EEEE, write FFFF to the Operation Com-
mand Request Bits to restart communications.
Register parameters in the Programless Upload
Settings or Programless Download Settings of
the HFU only for Units that are connected.
Check the following and correct any problems,
and then restart operation.
• Check the communications line lengths (trunk
and branch).
• Check the communications line for shorts,
breaks, or looseness.
• Check that terminating resistance is set only
on the ends on the trunk line.
• Check for excessive noise.
Correct the operation code in the ladder pro-
gram in the PLC.
Section 8-2