ControlLogix Tag Value 0 from RIO slot

First, I'm new to controllogix and not savvy on the tag system. Hoping to score some classes from the company soon! In the mean time, I have a contollogix sytem with 5 (1771-ASB)1/2 racks on RIO. This machine has never been operated. Rack 2 has a discrete DC input card in a slot that is receiving a binary position input from a Tempsonics transducer card. The input card in receiving input (can visually see the various inputs on thus an integer should be able to be extracted by referencing the slot).

In the program, a tag referencing the slot is in a MVM (Masked Move) as the source. The value of the tag is always reading 0000 0000 0000 0000. Any suggestions on where to begin or better yet end.

I can be more specific when I return to work tommorrow. Just plaguing my mind now.

Can you post pics of your MVM, and your I/O Configuration.

I can help, done loads of 1771 I/O on ControlLogix, just need to "see" the problem...

welcome to the forum ...

you really need to post your complete ACD file on this one ... use something like WinZIP to zip it first - then attach it right here in this thread ... better yet, also do a "File Save As" operation and save the program file in a L5K format - then zip and post that too ... that will help any forum members who might not have the same version of RSLogix5000 that you're using ...

another GOOD idea would be to post all of the DIP switch settings (usually 12 or 14) on the 1771-ASB adapter module from the chassis that's giving you the problem ...

also tell us what series 1771-ASB module you're using ... (A, B, C, D, or E) ...

also, post all of the settings from the 8 DIP switches on the chassis backplane that's giving you the problem ...

also, tell us exactly what slot the "problem" module is located in ... tip: do NOT use slot numbers for this ... instead LETTER the slots from left to right ... example: Slot A contains the ASB adapter ... Slot B contains etc., etc. ...

all of this information is necessary to nail down the specific address of the module you're having trouble with ... based on what you've posted so far, ("this machine has never been operated") - it's entirely possible that you have something set wrong (DIP switch, etc.) that's causing your problem ...

Thanks, Will give more info tommorrow.

Here's the rung and RIO breakdown.

Here's the tag. The ACD is too large to post.

You have a couple of layers of indirection here. Maybe they came from PLC5 translation, maybe they're somebody's standardization idea, maybe they're in place for a buffering reason. I can see how they cause confusion.

You're evaluating an INT tag called I_022. We can see from your rung posting that it's an alias for element 18 of an array called I[x].

There's probably a MOV or COP or other statement that moves the actual base tag for the RIO rack into that I[x] array, or at least there should be. I can't otherwise see the connection between I[x] and the actual RIO adapter base tags.

What I would do is replace I_022 with the actual base tag, which think is RACK_2:I.Data[2]

[0:0] RIO-MODULE OAD2    RACK_2:O.Data[0]

[0:1] RIO-MODULE IAD2    RACK_2:I.Data[0]

[1:0] RIO-MODULE OAD21   RACK_2:O.Data[1]

[1:1] RIO-MODULE IAD21   RACK_2:I.Data[1]

[2:0] (not defined)      RACK_2:O.Data[2]

[2:1] RIO-MODULE IBD     RACK_2:I.Data[2]

[3:0] RIO-MODULE VHSC    RACK_2:O.Data[3]

[3:1] (not defined)      RACK_2:I.Data[3]

First thing I notice is that I_022 is not aliased to an I/O tag - but to word 18 of an array called "I" - how is this tag getting the input data.....

I'll stop typing now because Ken has said all I was going to...