I hate to ask this but?

plc noob

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Join Date
Oct 2007
Location
atlanta , georgia
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258
I have a slc 5/05 and a micrologix 1500 in an old grinder control system. This machine had all the controls torn out and new controls installed by an integrator that has been out of buisness for over 10 years.

The machine will not run and i can not get into the plcs because they are both password protected. The micrologix is not controling much as best i can tell because we only have about half the paper prints and no cad drawing either.

I know how to clear out the password and i have an excel sheet with addresses and some comments so i can rebuild the documentation partially if i can get into the processor.

I know we do not discuss this in the open on this forum but if someone could PM me with any help i would be very grateful otherwise i have some bad days ahead.

Normally i would just rewrite it but htis equipment is part of the only line we are selling product from right now because of the economy so i really need to get it running fast and i don't have time to reverse engineer and rewrite.

Thanks
 
Well, my first question would be "what changed?" It has obviously worked in the past. The program hasn't changed, but something has... Being able to get into the program would be nice, but it isn't necessary (yet)

What happened immediately preceding the machine stopping?

There are some lights on the PLC -- what do they tell us?

Is there any other physical damage -- perhaps a sensor that's out of alignment??
 
As an RA Field Service Engineer, I do this sort of thing occasionally.

All you have to do is sign a form asserting your ownership of the code, and an RA FSE can unlock SLC or MicroLogix controllers with a little help from Tech Support.

It's a legitimate way to handle this issue, fast.
 
I agree with Ozee. If no one has touched the program that is not your problem - I would bet a paycheck on that. What I have found is some sensor is not working OR one of the comm cables or more likely the cable plug is not contacting well.

Go thru and check for all comm cables plugged in - you can clean them with one of those compressed air cans or 5 psi air. If done carefully isopropyl alcohol works well - let dry first.

Next check all inputs operating including the mechanical portion. Quite often I found the linkage not adjusted or the valve shut off on a pressure sensor.

Dan Bentler
 
Well the field service think would work but that will be my problem as this site manager will not use ab field support.

He claims he got burned like that before and will not even talk about that option.He will have me here working double to try and rewrite it.

They have a problem with the service and the price of ab field support.This is something that happened before i came here.

We had a drive problem a while back that we needed field support help on.We ended up replacing an 800hp drive with a different brand before calling field support.

This is a grinder nothing special about it and it is not any kind of innovation in grinders.I would just rewrite if i had full prints or something to work with but as it stands i am working very blind.

I have been through everything i can think of checking sensors looking at the i/o labeling that i have but still can't seem to get it to run.
 
Well the field service think would work but that will be my problem as this site manager will not use ab field support.

He claims he got burned like that before and will not even talk about that option.He will have me here working double to try and rewrite it.

They have a problem with the service and the price of ab field support.This is something that happened before i came here.

We had a drive problem a while back that we needed field support help on.We ended up replacing an 800hp drive with a different brand before calling field support.

This is a grinder nothing special about it and it is not any kind of innovation in grinders.I would just rewrite if i had full prints or something to work with but as it stands i am working very blind.

I have been through everything i can think of checking sensors looking at the i/o labeling that i have but still can't seem to get it to run.

Hmmm seems to me management has some choices
1. Get AB support to let you get into program to see what is going on.
2. Let you keep doing hunt n peck.
3. Replace the whole thing.

DOWNSIDES
1 Gonna cost a few bucks and oh lawzy they have to swallow their pride.
2. Lost production
3 Lost production. More bucks to replace.

Hmmm let us check the basics
1. Power is on to everything no blown fuses etc
2. all power supplies have proper output
3. PLC is in RUN
4. PLC is not faulting
5. All inputs are OK and input lite on PLC is on when input is correct?
6. Outputs - blown output card ?? Shot output relay??
I am not sure how you are going to trouble shoot these without knowledge of the logic. YOu gotta know which inputs must be satisfied to get the output. Without the prints and documentation you are in for some work. worst case is trace all wiring and do a bunch of head scratching rebuilding program off your head
WHILE mgmt is running around in circles screaming and shouting and just putting you closer to nervous breakdown.

Dan Bentler
 
Well the field service think would work but that will be my problem as this site manager will not use ab field support.

He claims he got burned like that before and will not even talk about that option.He will have me here working double to try and rewrite it.

They have a problem with the service and the price of ab field support.This is something that happened before i came here.

We had a drive problem a while back that we needed field support help on.We ended up replacing an 800hp drive with a different brand before calling field support.

This is a grinder nothing special about it and it is not any kind of innovation in grinders.I would just rewrite if i had full prints or something to work with but as it stands i am working very blind.

I have been through everything i can think of checking sensors looking at the i/o labeling that i have but still can't seem to get it to run.
I don't get it!
I have a hard time understanding how the site manager thinks to begin with.
IF it is a high priority and it sounds like it is and you need the production and AB can get you going regardless what they charge, then why on earth your site manager won't place the call?
And how having you working double shifts without documentation and such will save him money?
Not to mention the time the line will be down without a single "hot" product coming out of it?
I assume they do not teach Common Sense in MBA institutions!
 
I know it may not be of much help, but as a once noob a long time ago, spent a lot of time troubleshooting a machine to no avail.

The Sr. Operator walked up to it an unlatched the emergency stop button, and all went humming along. o_O
 
Thanks for the help guys we got it going.

It was sort of a programming problem if a pot that is normally used in hand is not below a certain value in auto the machine will not start.That was a very stupid design i removed that logic from the auto portion of the program as it should have never been there.As long as the pot was turned down it would start and this is something we did not check because the pot is just for manual control.

Thanks
 
Google is your friend, check your PM's. I sent you some keywords to search for. Also , I'm curious, how did you make the logic changes without the password access?
 
Last edited:
I know it may not be of much help, but as a once noob a long time ago, spent a lot of time troubleshooting a machine to no avail.

The Sr. Operator walked up to it an unlatched the emergency stop button, and all went humming along. o_O

E Stops !!!! After all the times I forgot one how could I have ever forgotten to mention them?

Dan Bentler
 
Google is your friend, check your PM's. I sent you some keywords to search for. Also , I'm curious, how did you make the logic changes without the password access?

I also would like to know how the changes were made with out the password ??

Sorry but someting does not sound right to me!!!!
 
I found the com lite method bya google search and had great success with it.The ab master backdoor password does not work with micrologix.

I had to clear the micrologix and rewrite but it was not doing much
 

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