Critique my code

I don't code very often, but I appreciate good advice, so I am asking for some criticism.

[Long story]We have an old Hydraulic Press that was run by an old SLC 100 with an Expansion module, and it lost it's last remaining extra output. I replaced the PLC with a Micrologix 1200.
One thing that I learned on this Forum was to run the power for the E-stop from a PLC Output so that if your Processor faults, the motor will shut off.
I decided to add a timer so that if they leave the motor idling for 2 minutes then the PLC will automatically shut off the motor.[/Long story]

I was worried about overflow faulting the processor on accumulated minutes, hours.
Do I really need to put the rungs 3 and 4 in there?
That was my main question, but it's all fair game.
Thanks

I would say that rung 3 is not needed since rung 2 takes care of limiting the value.
I would keep rung 4 else the plc may fault after about 4 years.

I usually just reset the overlow bit on the last rung, and then latch a bit, instead of trying to cover every possibility.
If I see the bit going true, I investigate to determine cause.

AJZ said:

I would say that rung 3 is not needed since rung 2 takes care of limiting the value.
I would keep rung 4 else the plc may fault after about 4 years.

Click to expand...

Thanks AJ that makes sense.

Ken Moore said:

...
If I see the bit going true, I investigate to determine cause.

Click to expand...

Thanks Ken, I have a different machine where the PLC has faulted on more than one occasion.
When it faulted, I just reinstalled the program.
I'll use your trick to see if I can find out why.

If the overflow flag on the last rung goes true, you can add the same logic at strategic locations in your ladder, but use a different bit/flag for each one, then you have a good idea which section of logic is the cause.