Not a Siemens Expert

A brief recap of my situation:
Siemens S7-200 PLC (214-1BD23-0XB0) with 2 Expansion Modules connected to a TD200.
One of the relay outputs intermittently locking on. Download the program and identify the failing output in the program. Swap out to a spare output in one of the expansion modules, download to the PLC and test, everything working fine.
Customer asks for a replacement PLC to prevent other outputs from following down the same path, fair enough.
Purchased a new processor, installed the saved copy of the original program prior to my readdressing patch, and installed. Had to adjust the two pots (SM28 and SM29) and figured I was done.
Production testing showed some sequencing issues with a section of the machine that had nothing to do with the readdressed output or the two pots.

My question is this: Would there be a setup screen in the TD200 that is overriding the downloaded program settings in the new PLC on power-up, or have I missed a step in the setup?

Hi

Never used the 200 series, but might it be possible the initial values for some timers or something could be wrong?

I have seen this in some standard machines using 300 series, the program was standard but the correct settings for that application were stored in a variable table VAT or could be set through the HMI

Soggy Canuck said:

My question is this: Would there be a setup screen in the TD200 that is overriding the downloaded program settings in the new PLC on power-up, or have I missed a step in the setup?

Click to expand...

Like boneless, I've never done much with the 200 series, but that sort of thing is definitely possible with most PLC systems. I've seen a lot of systems that store timer values and other setpoints in recipes in the HMI, or at least need to be set up from one.

Another possibility is that the "original" program you were given didn't actually match what was running. I can't count the number of times I've heard someone say "oh, well, it matched a while ago, it should be close enough, right?"

Had to replace a Chinese 200 with a US 1200. Assumed Q0.1 was first output, etc., but this wasn't the case. Nothing worked right. It was as if I totally miswired the Inputs and Outputs.

Turns out, you can reassign I/O on the 200. OEM must have done this intentionally.

The only thing I don't get, is the program I pulled from the original processor would have had all of the TD200 adjustments in it. When I re-installed the original it worked fine, so there doesn't appear to be a Cold start setpoint adjust coming from the HMI.

I pulled the complete running program from the original and saved it prior to modifying the code portion. This save procedure should have captured all of the setpoint (VB,VW), and there's no plugin memory module to be worried about.

I wasn't aware of any Firmware issues with the 200 series, but I guess anything is possible.

This sounds pretty odd, I have dealt with S7-200 a fair amount, but not so much with the HMI's.

I guess its safe to assume that you dont have a commented copy of the program that you would be able to troubleshoot easily?

Unfortunately not. If it was the comments would be in German. And we all know how well the translator programs deal with technical German.
Actually it borders on the absurd.

If thats the case, you just have to be prepared to crack 2 codes.

....It happens to me a couple times a year usually.