Conveyor system controlled by PLC

Thread Starter

JKDuke1996

Joined Mar 31, 2017
8
Working on a 34 year old Rapistan PLC which controls multiple conveyors. No one has a clue about the plc program, back ups or program documentation. Have performed troublehooting on the wiring, relays, switches. Any idea on how to extract the ladder logic from the plc? Thank you.
 

MaxHeadRoom

Joined Jul 18, 2013
23,635
Never heard of that PLC and I have been using them virtually from their inception.
Normally you need a PC program and cable for connecting.
But many of the older original ones had a special hand-held unit for this.
So it may take alot of searching.
Do you have any programming documentation on the unit at all?
It may be productive to look at a modern replacement and write a new program.
Add:
http://www.ebay.ca/itm/282344276985?rmvSB=true
Max.
 
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Thread Starter

JKDuke1996

Joined Mar 31, 2017
8
The conveyor system is Rapistan which has been bought and sold several times. This is a big distribution center built in the early 1980s. As far as the plc unit we don't know name or version. I think we are dead in the water until our customer can get the plc info for us. The dc has changed hands several times since the building was built and the new maintenance man has no clues. Thanks for the response.
 

Thread Starter

JKDuke1996

Joined Mar 31, 2017
8
"Prior to adopting the Dematic name, the company was known as Rapistan. For more Dematic information, visit www.dematic.us."
Thank you for the information. Yes I found that on the Internet. That company recommended someone from Ft. WORTH TO COME AND TROUBLESHOOTand it was a disaster. They were suppose to bring the proper stuff to test the plc. I'm wondering with the age of the plc if the ladder logic is linear? We have an associate with computer background who says he might be able to coax the info out if it is linear. Any thoughts?
 

shteii01

Joined Feb 19, 2010
4,644
Thank you for the information. Yes I found that on the Internet. That company recommended someone from Ft. WORTH TO COME AND TROUBLESHOOTand it was a disaster. They were suppose to bring the proper stuff to test the plc. I'm wondering with the age of the plc if the ladder logic is linear? We have an associate with computer background who says he might be able to coax the info out if it is linear. Any thoughts?
No idea.

One of the reasons your post attracted my attention is that I now work for a company that makes conveyors. I do electrical assembly so I am not very high on the totem pole. We mostly use AB PLC, AB VFD motor controllers, SMC for pneumatic. But if a few months from now you and your's decide you want a new one... I am sure my company would be happy to work with you.:cool:
 

MaxHeadRoom

Joined Jul 18, 2013
23,635
The one beef I have with AB is if the company requires S/W for trouble shooting, which is usually a given, AB want a small fortune for it.
I believe the S/W should be a relatively low charge for S/W if at all. After all you can only use it on their equipment.
Max.
 

tranzz4md

Joined Apr 10, 2015
310
You could probably find plenty of stuff about Rapistan on the internet, but they never made any PLCs for general use, and their controls were for vertical markets. Demag had their name on some big cranes, and some other heavy equipment.

Apparently, the original project folks only specified the desired function of the system and went low-bid, and ultimately your company bought that black box. Now, somebody wants you to step in and do things the original developers tech's worked hard to accomplish. Good luck.

You'd do well to obtain a hard copy of the ladder, or even the functional description.

Yanking that obsolete and unavailable controller, and installing currently available and popular hardware is the dirty, labor consuming part of the job that needs to be done. The new program is the fun/tricky part. I'd love the project, but not having the suit and tie guys look at this as though the air conditioning repairman just showed up and said "it can't be fixed, but I can give you a deal on a new one".
 

GopherT

Joined Nov 23, 2012
8,012
The conveyor system is Rapistan which has been bought and sold several times. This is a big distribution center built in the early 1980s. As far as the plc unit we don't know name or version. I think we are dead in the water until our customer can get the plc info for us. The dc has changed hands several times since the building was built and the new maintenance man has no clues. Thanks for the response.
How big is the system? Number of motors, sensors, eStops, etc.
 

Thread Starter

JKDuke1996

Joined Mar 31, 2017
8
No idea.

One of the reasons your post attracted my attention is that I now work for a company that makes conveyors. I do electrical assembly so I am not very high on the totem pole. We mostly use AB PLC, AB VFD motor controllers, SMC for pneumatic. But if a few months from now you and your's decide you want a new one... I am sure my company would be happy to work with you.:cool:
Thanks. We are just the electrical contractors called in to look at a "start/stop" issue. Turns out it is much more complicated. But, I will pass this on to their head maintenance man. Regards.
 

GopherT

Joined Nov 23, 2012
8,012
Thanks. We are just the electrical contractors called in to look at a "start/stop" issue. Turns out it is much more complicated. But, I will pass this on to their head maintenance man. Regards.
Rapistan was not a PLC manufacturer, they made the entire conveyor systems with their own PLC systems.
 
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Thread Starter

JKDuke1996

Joined Mar 31, 2017
8
How big is the system? Number of motors, sensors, eStops, etc.
That's one of the interesting part of this deal. We are only dealing with a third of the entire system. Sections have been pulled out and discontinued. But, unmarked relays and wiring are still hooked up. The sad thing is this is a national company with pockets deep enough to have been able to properly maintain, document or upgrade the conveyor system. I don't know if we will be called back for further work. There are multiple photo eye stations to stop product. Many on off switches. Multiple emergency stops mounted on columns. Plus, we have only been spoon fed bits and pieces of information on how it all should work. No one in the maintenance department has a complete grasp of the system.
 

Thread Starter

JKDuke1996

Joined Mar 31, 2017
8
Good luck. As said above by someone else, a ground-up retrofit would be easier than a repair.
That's is our take also especially after all the kind and helpful comments. We are only electrical contractors and have never ran into a situation where the system was so poorly maintained and they didn't have access to their plc programming or have someone who actually understands the plc logic. Thanks.
 
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