System Status References; Using The System Status References; S References - GE VersaMax PLC User Manual

9.3 System Status References

Reference
%S0001
%S0002
%S0003
%S0004
%S0005
%S0006
%S0007
%S0008
%S0009
%S0010
%S0011
%S0012
%S0013
%S0014
%S0015, 16
Program Data
For public disclosure
The PLC stores system status data in predefined references in %S, %SA, %SB, and %SC
memory. Each system status reference has a descriptive name. For example, time tick
references are named T_10MS, T_100MS, T_SEC, and T_MIN. Examples of
convenience references include FST_SCN, ALW_ON, and ALW_OFF.

9.3.1 Using the System Status References

System status references can be used as needed in application programs. For example, the
following function block uses the FST_SCN (first scan) status reference to control power
flow to a Block Clear function. In this example, at powerup, 32 words of %Q memory
(512 points) beginning at %Q0001 are filled with zeros.
FST_SCN
%Q0001

9.3.2 %S References

References in %S memory are read only.
Name
FST_SCN Set to 1 when the current sweep is the first sweep.
LST_SCN Reset from 1 to 0 when the current sweep is the last sweep.
T_10MS
0.01 second timer contact.
T_100MS
0.1 second timer contact.
T_SEC
1.0 second timer contact.
T_MIN
1.0 minute timer contact.
ALW_ON Always ON.
ALW_OFF Always OFF.
Set when the PLC fault table fills up. Cleared when an entry is removed
SY_FULL
and when the PLC fault table is cleared.
Set when the I/O fault table fills up. Cleared when an entry is removed
IO_FULL
from the I/O fault table and when the I/O fault table is cleared.
OVR_PRE Set when an override exists in %I, %Q, %M, or %G memory.
reserved
PRG_CHK Set when background program check is active.
Set to indicate a bad battery in the CPU. The contact reference is
PLC_BAT
updated once per sweep.
reserved
| |
IN
LEN
00032
Definition
GFK-1503E User Manual 117