Q's: Please explain rungs 10 and 11. On rung 11 you have an output O:0/12. Then on rung 10 you have an XIO instruction performing a logical AND NOT I:0/29. I:0/29 is labeled FROM OUTPUT O:0.0/12. Before I go jumping to conclusions, will you explain what the relationship between I:0/29 and O:0/12 is and what is wired to each one. The same thing exists at rungs 12 and 14 also.
A's:
Line 11's output 12 when true keeps the normally closed input of I:0.1/14 or I:0/29 open. Output 11 is only true when line 10's compare is true which means line 11's compare is false thus output 12 is false which in turns means I:29 is closed thus turning output 11 true. Output 11 affects inputs found in lines 7 & 10.
There are multiple operational modes involved here: auto, manual and remote. Based on the outputs, different operational modes react accordingly.
I hope that helps a little. Needless to say the original ladder program was written for a 305 Direct Logic PLC and my task was to convert the existing hard copy of that ladder program to a new version for a MicroLogix 1200 PLC w/Analog I/O model 1762-IF4.
Again, I do appreciate all advice / support and help that I have received. I have expertise in Sonet fiber optic operation / engineering - am a subject matter expert from T1's up to OC192's - if anyone ever needs any help in regards to telecommunications, I would be most happy to assist.
I am learning and understanding, the learning curve is not all that steep at this point - something that I think will start an upward climb soon.
Rodney.
