Brand spanking new to PLCs - real life problem to solve

I have been tasked with reverse engineering a large oven control system. The controller is a DC Omron controller.


My first two very high level questions are:

1.) Should I be able to purchase ZEN software, then interface to this unit and review the present program in this unit in order to attempt to reverse engineer this oven control?

2.) Can I do this without the ZEN software simply by viewing the LED from panel (once I learn how to read the front panel)?

At this point all I want to do is to understand the basic functionality of this massive oven. I believe it has three parts, oven control, fan control and some sort of a turbine all working as a feedback control unit. But to begin with all I have to go on is a bunch of contactors, relays and a ton of wires and this DC Omron controller. I'm thinking if I can understand the program I can decode the rest of the unit.

Any help much appreciated.

I am not a Omron user, but I think it would help someone help you if you could provide the complete model number of the controller you have.

The unit is:
10C1DR-D_V2

It has an expander:
8E1DR (for a total of 10 I/Os)

I agree with Mickey, I am more familiar with other PLCs. However, if you can write out what you see happening, influencing what you can in your i/os, and what you want happening, that will be your logic or "code". What aspect of your system are you wanting to view, modify or improve upon? Model of your PLC? When you say LED, are you referring to face of the Omron, or an HMI? Do you have I/Os displayed on a screen in your HMI? Any schematics to identify your I/Os?

I am sure you have already seen, but just in case..
http://www.ia.omron.com/data_pdf/cat/zen_ds_csm106.pdf
interesting section on the difference between it and a PLC

If you plan to use a different controller I would not need to see what's in the old one but rather spend time deciding how you want the system to operate. Then choose and learn your new control.
You may want to look into updating the old clic-clak contractors to solid state too.

If you plan to use a different controller I would not need to see what's in the old one but rather spend time deciding how you want the system to operate. Then choose and learn your new control.

Click to expand...

I agree with this 100%. It's seldom worth the time and effort to look at old programs and reverse engineer.

Better to find out how it's suppose to work by talking to operators, study the HMI or buttons if any and look at the electrical drawings.

Often there are functions that need to be added or changed anyway. Sometimes there are safety related things that need to be upgraded as well to comply with current regulation.

jri4au said:

I agree with Mickey, I am more familiar with other PLCs. However, if you can write out what you see happening, influencing what you can in your i/os, and what you want happening, that will be your logic or "code". What aspect of your system are you wanting to view, modify or improve upon? Model of your PLC? When you say LED, are you referring to face of the Omron, or an HMI? Do you have I/Os displayed on a screen in your HMI? Any schematics to identify your I/Os?

Click to expand...

Yes, the LED is the small display on the face of the unit.

This unit as it stands right now is in shambles. There is no power to it and will not be until we can get upgraded power from the street (2-3 weeks) The oven came from another country. The primary function of the oven is known but the feedback mechanisms are not. Many of the wires to the contactors and relays are cut or disconnected. Why they did this before shipping it I have no idea and no way to find out. There is no wiring diagram. No schematic of any kind. Any labeling is in Spanish so I have to translate. So my initial task with this is to get a rudimentary idea of how this all worked together. Put it back together and eventually try it out.

Again we know from a basic standpoint what we need to do with this oven but we do not know how the feedback mechanisms work at all. I have to ring this whole thing out (feedback control box and power control box) And of course, we are working under dramatic time constraints so a redesign is out of the question in the short term. Probably will happen eventually.

I only have time to attempt to piece this all together and attempt to fire it up. My only short term option is to learn what is there (supposedly it was working before being carelessly disassembled and shipped to the states).

This is the reason I need to learn how this PLD was programmed. Being the central brains of the unit, I think I'll be able to figure it all out if I know how it was programmed. And again, I am new to PLDs....whoopy!

Thanks

I would do the one of the or all of the following.

Power controller only. Purchase zen soft ware and cable and up load program. Program will not have comments. You will access to the I/O list from this for control wiring confirmation.

Power controller only and scroll thru program via the screen, and write down an I/O list for control wiring confirmation.

Once you have your list start with inputs, trace each one at a time. Do the same for outputs.

The local Omron distributor is Pearse-Bertram in Bloomfield CT.

http://www.pearse-bertram.com/

Give them a call. They have a decent technical staff.

Boorabee Parker said:

I would do the one of the or all of the following.

Power controller only. Purchase zen soft ware and cable and up load program. Program will not have comments. You will access to the I/O list from this for control wiring confirmation.

Power controller only and scroll thru program via the screen, and write down an I/O list for control wiring confirmation.

Once you have your list start with inputs, trace each one at a time. Do the same for outputs.

Click to expand...

Thanks, this is what I was essentially asking; if it were possible for the controller to output the program to the screen such that I can decode it. I'll give this a shot. I'll also likely be contacting the technical staff for assistance as Steve suggested.

Have you approached the manufacturer of the oven for assistance? It may be costly, but if time is a prime issue...

question has evolved into a simulation question

Hi All,

Thanks again for your inputs. I have acquired Omron Zen software and now have a question on the simulator.

(I do not know how to attach images so I will try to describe in words)

When the simulator is invoked there are two main displays that appear, the ladder diagram along with a display that simulates the PLC physical front panel.

As I step through the program (all rungs are on a sequential timer) I can see the ladder diagram progressing through the steps as the timer advances. However I never see the outputs become illuminated.

Clearly I am missing something very basic. What might I be not doing that I need to do to see both the ladder diagram and the outputs simulate the program? (This by the way is a working program, it has worked for a long time in the application, so there are no bugs in the program)

Thanks

I figured it out, there were some logic inputs I needed to address!

Instead of reverse engineer it, or trying to understand the code, when I am replacing the PLC,I always ask what it should do and make a brand new programm