MVI56E-GSC ControlLogix ASCII Module

Good morning ALL,
I am having a hard time figuring out the way this module sends and receives data...I have done all kinds of comm protocol before but never ASCII. What I don't get is how I put something like " I201 " in a decimal tag (GSC.DATA.Port1.WriteString). There must be something I'm missing.
Thank you,
T.J.

Have you got the AOI for the module?

usually the Prosoft manuals are very good and describe everything

A String in ControlLogix consists of a .LEN element (a 32-bit DINT) and a .DATA array.

The .DATA array is a 1-dimensional array of 8-bit SINT elements, so each element is a single ASCII character.

My recollection is that the .DATA element of the MVI module's big complex User-Defined Datatype is also a SINT[x] array.

So to take data from a String in your program and put it into the .DATA element for the MVI module, just copy YourStringTag.Data[0] to GSC.DATA.Port1.WriteString[0], with a Length argument in number of characters.

I might be one step back in complexity; maybe WriteString itself also has .LEN and .DATA sub-elements.

Either way, the COP and CPS instructions are what you will use to perform the data movement.

Thanks

Gents,
Thank you for your help.

Michael, I do have the AOI installed and I looked at the sample ladders that Prosoft provides. It looks like the samples are setting the clock via ethernet or something.....not really what I'm looking for. The AOI is definitely important though.

Ken, I will give that a try. I think my biggest challenge now is making sure the device (Veeder-Root TLS-350) is going to accept the strings the Prosoft is sending out.

Thanks again guys,
T.J.