Micrologix1200 help please

Good day all. I am troubleshooting a Micrologix1200 (1762-L40BWA) with a Bul.1762, ser C processor. I have two questions, please. I have the publication 1762-UM001G-EN-P-March 2011 manual and have perused it but I can't find this info. First, it has two expansion modules. I have disconnected the ribbon cable from the PLC and attempt to create a new project. When I do and I select "Read I/O Config" from the I/O config page, it still shows the expansion modules, even though they have been disconnected. I looked for possible jumpers or dip switches but could not find any. I found dip switches on the expansion modules but not on the PLC itself. I checked to see if somehow it was configured on an image table some where but found nothing. The reason this is significant is because I am getting a processor error that says "The controller can not communicate with expansion I/O module 1". I was trying to determine if the problem is in the ribbon cable, which it doesn't appear to be.
Second, when I turn on and off the inputs, the LED's on the control light and extinguish however, watching the I/O image table, it does not update. This could be attributed to the faulted processor but I am not sure. I appreciate any help that can be offered. Thank you.

Another question, please. The trim pots on the front of the control are supposed to allow modification of the data within the controller. What exactly does that mean? Thank you

The trim pots have an address in the function files section under the TPI tab, you can use this address in your program as a analog value,

Alan

is this thing on any sort of network? ... and if it is, are you absolutely SURE that you're connecting to the right processor? ...

when I turn on and off the inputs, the LED's on the control light and extinguish however, watching the I/O image table, it does not update.

Click to expand...

most processors that use RSLogix500 must be in the Run mode in order to update their input tables ... note that this is different from most PLC-5 processors that you might be more familiar with ...

When you say you are turning on and off inputs and outputs,
how are you doing this are you FORCING the I/O.

Ron Beaufort said:

most processors that use RSLogix500 must be in the Run mode in order to update their input tables ... note that this is different from most PLC-5 processors that you might be more familiar with ...

Click to expand...

Yup, that was it. With the PLC-5 and the SLC500 processors I have worked with I was able to use Remote Program and it worked. I had to put this in Run, which it wouldn't do because the processor was in fault mode. I cycled power to the PLC and the fault went away. All I did was remove the ribbon wire connector and then put it back. Must have been something in there it didn't like. Thanks Ron

alan_505 said:

The trim pots have an address in the function files section under the TPI tab, you can use this address in your program as a analog value,

Alan

Click to expand...

Could you please give me an example. I am still having trouble wrapping my head around this. Thanks Alan.

The trim pots are addressed as "TPI:0.POT0" and "TPI:0.POT1". These are 16-bit integer registers that contain the current positions of the two single-turn potentiometers. The range is 0 (fully CCW) to 250 (fully CW).

You can use these addresses in any instruction that reads a word address. The following would turn on the output if the pot is turned past the halfway point.

I really wish we had a way to give a thumbs up to a post that helps us or we like to help weight the answers/comments in the forum. Thanks for the examples Kolyur and Ron.\\




Kraken Fan #69

Thank you for this information. I wasn't able to try it until today. That's a pretty cool feature! Also, comparing and contrasting the RSLogix500 from a SLC500 and this Micrologix1200, there are many things that are different. I was under the assumption (never had to any serious work on the Logix1200) that they were identical. You all have helped a lot. Thanks again.