Undefined I/O address:

We just purchased an 1747-L120C and is not successful programming it. Get Undefined I/O address when trying to program any input or output other than 0. Can do anything with input and output 0 but inputs 1 through 11 and outputs 1 through 7 results in undefined I/O address errors when compiling. Any help here will be appreciated.

Be careful in your posting. There is no such thing as an L120C. There is an L20C which has a few I/O on the main unit. They will have the form I:0/xx an O:0/xx for inputs and outputs respectively. There are a total of 20 I/O on it (hence the '20' in the name.)

An easy way to select these, assuming you are using RSLogix 500, is to open the input table then, what you have put into place a XIC or XIO contact, click and drag one of the positions in the input table to the contact then release it.

Also it would be best to post next in the main forum instead of the practice area.

Sorry for the typo. We're using a 1747-PLT to program this unit. As a note, we've programmed other L20C's with it so we don't suspect the hand held at this time. Being an real amateur on this product, we're wondering if we're over looking some kind of setup or configuration that is not called out in the user manual.

thx...edo

Wow, I knew the existed but never used one. The input and output addresses are still entered with the longer format. (e.g. I:0/5) Maybe you can take a snapshot (camera) of a rung before attempting to compile and after.

Undefined I/O address error:

Okay, the following is what works and doesn't:
Works -
[XIO] I:0/0__________________________[OTL] O:0/0
[XIC] I:0/0__________________________[OTU] O:0/0

Compiles ok and runs.

Don't work -
[XIO] I:1/0__________________________[OTL] O:1/0

Generates undefined I/O address error during compile.

Could this be a defective control? Sets up as a 1747-L20C/F and rnns the ladder program using input and output 0 only. Won't compile anything else.
If you want to see photos of the ladder, configure file, and data files, I think we can do that and e-mail them to you.

thx...edo

You probably have this manual. Page 4-4 may provide some help.
Link:
http://literature.rockwellautomation.com/idc/groups/literature/documents/um/1747-um021_-en-p.pdf

The unit can accept a two slot add-on rack. The addresses you attempted to use would belong to a card in the first of the two slots. The card would have to have both input and output capabilities. In RSLogix 500 any such card must me added to the I/O configuration before they can be used in a program. Does the handheld device allow for I/O configuration?

Bernie, i dont think he has an Add-on card, rather that he istrying to adress more of his built-in I/O.

ED, if this is true, here is the problem: the number you are changing, is the slot number. the number after the / is the I/O number.
So it should go like this:
I:0/01 =built-in input 1
O:0/01 =built-in Output 1
I:0/02 =built-in input 2
O:0/02 =built-in Output 2
I:0/03 =built-in input 3
O:0/03 =built-in Output 3
and so on, do you understand what i am saying? i hope that helps you out.

Problem resolved...thank you all for your inputs. With your all of your heip got our heads out of that dark tunnel and resolved our programming problem.

Thank you all again...great forum!

edo.