User Manual
Chapter 9
GFK-1503F
Jan 2020
Program Data
95
9.3.3
%SA, %SB, and %SC References
References in %SA, %SB, and %SC memory can be both read and written to.
Reference
Name
Definition
%SA0001
PB_SUM
Set when a checksum calculated on the application program does
not match the reference checksum. If the fault was due to a
temporary failure, the discrete bit can be cleared by again storing
the program to the CPU. If the fault was due to a hard RAM failure,
the CPU must be replaced.
%SA0002
OV_SWP
Set when a PLC in CONSTANT SWEEP mode detects that the
previous sweep took longer than the time specified. Cleared when
the PLC detects that the previous sweep did not take longer than
specified. Also cleared during transition from STOP to RUN mode.
%SA0003
APL_FLT
Set when an application fault occurs. Cleared when the PLC
transitions from STOP to RUN mode.
%SA0004-8
reserved
%SA0009
CFG_MM
Set when a configuration mismatch is detected during power-up or
a configuration store. Cleared by powering up the PLC after
correcting the condition.
%SA0010
HRD_CPU
Set when the diagnostics detects a problem with the CPU hardware.
Cleared by replacing the CPU module.
%SA0011
LOW_BAT
Set when a low battery fault occurs. Cleared by replacing the battery
then powering up the PLC.
%SA0012,13
reserved
%SA0014
LOS_IOM
Set when an I/O module stops communicating with the CPU.
Cleared by replacing the module and cycling system power.
%SA0015
LOS_SIO
Set when an option module stops communicating with the CPU.
Cleared by replacing the module and cycling power on the main
rack.
%SA0016-18
reserved
%SA0019
ADD_IOM
Set when an I/O module is added. Cleared by cycling PLC power and
when the configuration matches the hardware after a store.
%SA0020
ADD_SIO
Set when an option module is added. Cleared by cycling PLC power
and when the configuration matches the hardware after a store.
%SA0021-26
reserved
%SA0027
HRD_SIO
Set when a hardware failure is detected in an option module.
Cleared by replacing the module and cycling PLC power.
%SA0028-30
reserved
%SA0031
SFT_SIO
Set when an unrecoverable software fault is detected in an option
module. Cleared by cycling PLC power and when the configuration
matches the hardware.
%SB0001-9
reserved