Programming the Local Host
Chapter 5
534
033
00
Local Fault
L
010
00
033
10
Remote Fault
Indicator
Output
U
010
00
032
00
Done
Indicator
Output
This example shows the fault bit monitoring for as many as eight
commands. The eight remote fault bits and the eight local fault bits reside
in Word 033. In Rung 1, the status of the fault bits is compared to the
constant zero. The comparison controls an OFF-delay timer. The
OFF-delay timer begins to time when all the fault bits go OFF after one or
more has been ON.
Bit 03015, the timed bit of the timer, controls the output indicator. As
soon as a fault bit goes ON, this bit goes ON, thereby turning on the
indicator. Once ON, the indicator remains on as long as the timer is
timing; that is, for at least as long as the preset interval. In the example of
Figure 5.22, this preset is two seconds. We recommend this value be set
at no less than 0.5 seconds.
Figure 5.22
Fault Bit Diagnostic Rungs (Multiple Commands Example)
TOF
030
0.1
040
000
G
Constant
010
00
030
15
Timed Bit
Indicator
Output
Rung 1
Rung 2
PR 020
AC 000
033
000
<
Fault
Status
