393
The type of error can be quickly determined from the indicators on the CPU, as
described below for the three types of errors. If the status of an indicator is not
mentioned in the description, it makes no difference whether it is lit or not.
After eliminating the cause of an error, clear the error message from memory
before resuming operation.
Asterisks in the error messages in the following tables indicate variable numeric
data. An actual number would appear on the display.
Initialization Errors The following error messages appear before program execution has been
started. The POWER indicator will be lit and the RUN indicator will not be lit for
either of these. The RUN output will be OFF for each of these errors.
Error and message FAL no. Probable cause Possible correction
CPU WAIT G
Waiting for Special I/O
or Interrupt Input Units None A Special I/O Unit or
Interrupt Input Unit has not
initialized.
Perform the I/O Table Read
operation to check unit
numbers. Replace Unit if it
is indicated by “$” only in
the I/O table.
(High-density I/O Units will
not appear on I/O Table
Read display for all
peripheral devices.)
CPU WAIT G
Waiting for Remote I/O None Power to Remote I/O Unit is
off or terminator cannot be
found.
Check power supply to
Remote I/O Units,
connections between
Remote I/O Units, and
terminator setting.
Non-fatal Operating Errors The following error messages appear for errors that occur after program execu-
tion has been started. PC operation and program execution will continue after
one or more of these errors have occurred. For each of these errors, the
POWER and RUN indicators will be lit and the ALM/ERR indicator will be flash-
ing. The RUN output will be ON.
Error and message FAL no. Probable cause Possible correction
FAL error
SYS FAIL FAL**
01 to 99 FAL(06) has been executed
in program. Check the FAL
number to determine
conditions that would cause
execution (set by user).
Correct according to cause
indicated by FAL number
(set by user).
Interrupt Input Unit error
SYS FAIL FAL8A
8A An error occurred in data
transfer between the
Interrupt Input Unit and the
CPU.
Replace the Interrupt Input
Unit.
Interrupt subroutine error
SYS FAIL FAL8B
8B Interrupt subroutine
containing Special I/O Unit
refresh was too long.
Cyclic Special I/O Unit
refreshing was not disabled
for interrupt subroutine
refresh.
Check the interrupt
subroutine and PC Setup.
Error Messages Section 10-4