1762-IF2OF2 Analog Input Problem

[93lt1]

There is no “rack” for the MicroLogix1200 - the expansion modules for this system just snap onto the DIN rail with the processor and are connected to the processor by a ribbon cable.

Thats why I said:

the main rack (so to speak).

Meaning not in one of the "positions" connected through the expansion cable.

 

[davidgay]

Ladies & Gentlemen:

EUREKA!! After much struggle I have determined that the problem IS a DEFECTIVE analog card. The inputs are miswired or something... when IN1(-) and IN0(+) are connected to 4-20ma the counts in Input0 change and likewise when IN0(-) and IN1(+) are connected to complete a circuit the counts change for Input1. Is that weird or what??? I've been using the terminal labeling on the card and it matches the labeling on page 9 of the Micrologix Analog Input/Output Module and wiring the card as shown on page 10... but that just isn't the way this animal is wired... My AB rep is going to check and get me a replacement for the defective card... I thought it was just a labeling problem, but the card still doesn't work correctly even when using the above scenerio...

Again I want to thank everybody for their inputs... I'm not an insane controls guy after all (but I play one on TV) LOL

I can joke about it now but while ago I was REALLY getting frustrated!
I didn't think I had that much patience, but with your help we've made it through... Thanks again!

 

[93lt1]

Meaning not in one of the "positions" connected through the expansion cable.

Or is there an expansion option? (similar to the Micrologix 1500?)

 

[Ron Beaufort]

Dear 93lt1:

An apology ...

Judging from one of your earlier posts, it seems that you might have misinterpreted my “no rack” comment as having been directed toward you personally. That was certainly not the way I intended it. Looking at the stats on this thread, I see that there have been (at present) 15 replies – and (a much larger number of) 182 views. That means that there are many people reading over our shoulders as we write these posts. I assume that at least some of these people are there trying to learn. Yesterday it occurred to me that some of these “learners” might have absolutely no experience with the relatively new MicroLogix1200 platform. To make the situation a little more understandable to them, I went to the trouble of posting a link to a diagram of the hardware and tried to draw their attention to the fact that there is no “rack” involved in this system. I certainly didn’t mean to imply that I was “correcting” something that you had said in your earlier post. (I did, in fact, pick up on your parenthetical notation). If you did interpret the intent of my comment as a “correction”, then I apologize for not having been more careful with the way I expressed myself. In hind-sight I now realize that I should have addressed the post in question expressly to the “newcomers” in the “audience” rather than simply to “Friends and neighbors”.

In my opinion, one major disadvantage of communicating through this type of forum is the inability to convey the many verbal and visual cues which are available to us in face-to-face conversations. Personally, I tend to write much more verbiage than most people do – in many cases I do this in a conscientious effort to minimize misunderstandings and misinterpretations of the “tone” of my “voice”. I am always afraid that a “concise” statement, one which would be perfectly appropriate in a face-to-face conversation, might be taken as vindictive or sarcastic when placed in writing. That having been said, it is entirely possible that I have inadvertently misjudged the tone of YOUR "offended" post – and that this well-intentioned apology will do nothing but truly offend you. If that is the case, then I am indeed sorry.

Finally, I thought long and hard about sending this to you in a private message – but decided to make this a public apology instead. Hopefully others can learn something from it. This forum should be a cooperative effort – not a competition. We should all try to ensure that what we write encourages and builds-up others. I myself have conscientiously been trying to do that – apparently I need to try harder.

Sincerely,

Ron

P.S. It seems that David got his problem fixed while I was typing this. Congratulations.

 

[93lt1]

No apology needed!
I agree with your "not being able to convey the true meaning of what we are trying to say by typing" idea. I didn't mean to give you the "offended" look. I was merely trying to clear up what I meant. I all too often type things, and moments after realize that what I typed is completely unlike what I was trying to say.

I do see how you thought I was offended. I really wasn't.

 

[john paley]

I looked at your connection diagram. Where's the loop power supply?? 4A 4-20 mA loop needs a power supply. No power, no current.

 

[davidgay]

John,

The 4-20ma current is being supplied by the instrument that is measuring the temperature, it has its own external power supply. I have talked with my AB rep. and he has verified the wiring, etc. the problem has been determined to be a defective 1762-IF2OF2 Analog module. The module is currently being replaced by AB and should arrive later today for testing.

I appreciate all the assistance I have received from the people who have responded to my post and want to thank you all again for the help.

Everyone have a wonderful day, I am now that this problem has been resolved. Thanks Again!

 

[w_thanong]

I use Micrologix1100 and explantion 1762-IF4 and 1762-IF2OF2 I config and wiring and test but use 2 wire for 1762IF2OF2 ANALOG input Reading unstable 2 points i Follow Manual but it still reading unstable