Allen-Bradley ClutchBrake PLC-5 Series - Using Fault and Prompt Bits

4–19Write Ladder Logic
Publication 65566.5.1 - October 1996
For example, if processor A monitors position with resolver inputs
and processor B controls all pilot lights for press operational status,
processor A could transmit the status of top dead center to processor B
as follows (Figure 4.23):
Figure 4.23
Example
Logic to Exchange Data Over a Scanner/Adapter Channel
| Processor A |
| |
| +LES––––––––––––+ +GRT––––––––––––+ O:027 |
+––+LESS THAN +––+GREATER THAN +––––––––––––( )––|
| |Source A N40:0| |Source A N40:0| 01 |
| |Source B 5| |Source B 355| |
| +–––––––––––––––+ +–––––––––––––––+ |
| Processor B |
| |
| Press at Top Press at Top Top Dead |
| from Processor A to Processor A Cntr Light|
| I:027 O:027 O:010 |
+–––] [–––––––––––––––] [–––––––––––––––––––––––––( )––|
| 01 01 00 |
We designed internal diagnostics such that when control logic detects
fault conditions or other conditions worthy of attention, it sets a
corresponding bit in either of two bit files:
•fault bits in B168/0-B168/159
•prompt bits in B169/0-B169/80
We provide you with a look-up table that states the type of fault and
suggests what to do to correct it. Refer to Appendix E and the
Operators Guide for identical look-up tables.
We suggest that you design a method to monitor these bits and
display the triggered condition, depending on the type of operator
interface you use. The following logic (Figure 4.24) generates a
BCD fault number whenever control logic sets a fault or prompt bit:
Using
Fault and Prompt Bits