Omron ZEN - 6-1 Troubleshooting

116
Troubleshooting Section 6-1
6-1 Troubleshooting
Search for the cause of the error and take immediate
countermeasures if ERR or any other error message appears on the
LCD screen (for CPU Units with display) or the ERROR indicator is lit
(on LED-type CPU Units).
6-2 Error Messages
The following tables list the error messages that are displayed when
an error occurs.
Power ON but No Operation
Note I/O Verification Error
Expansion I/O Unit I/O bits (X/Y): Bit not allocated in system
configuration has been used.
Analog comparators (A): Used with AC power supply type.
Weekly timers (@)/Calendar timers (∗): Used with ZEN with LED
displays.
ERR
ERROR
LED-type CPU Unit
without LCD
CPU Unit with display
Error message Probable cause Possible solution
MEMORY ERR Program error. The ladder program and parameter settings
have been cleared. Write a program to the
ZEN again.
I/O BUS ERR Expansion I/O Unit
connection error.
Turn OFF the power supply and check that
the Expansion I/O Units are connected
properly.
UNIT OVER More than 3 Expansion I/O
Units connected.
Turn OFF the power supply and reduce the
number of Expansion I/O Units to 3 or less.
I/O VRFY ERR Bit type that cannot be
used with system
configuration included in
ladder program. (See note.)
Remove the illegal bit type from the program.
Z211-E1-03.book Page 116 Friday, November 21, 2008 10:38 AM