Moving Strings in Logix 500

[joelolson]

I am trying to move a string data type (ST12:0) to (ST12:9) and other strings (1-8) into (ST12:9) depending on the state of a device. When I try to do this it gives me an Error: Address must be specified to the word level!

Any thoughts on how I can move strings around.

Thanks

 

[dmroeder]

You would use a COP, not a MOV

 

[GaryS]

I don understand the error but this may help
A MOV only move 1 word to a word of the same type
A MOV also moves the original data / Bits to the new location
A COP move arrays to and array of the same type the limit is 256 words at time
A COP copies the data to the new to the new location leaving the original data in tact
the copy is a better way to copy data len of 1 will copy 1 word

the other thing AB treats all strings as arrays of values a string of 10 characters will be an array of 10 sint ( ASCII)
when I set you the simulation of what I think you are trying to do I could only copy 3 strings of the array at a time the error I got back said I exceeded the 256 word limit
Working with string is a little different and requires some thought

 

[joelolson]

dmroeder-
Thanks for the answer. I did need to use a COP instead of a MOV and it solved my problem. Still a little confusing because the COP asks for a length but its not the length of the String register. I was able to copy a 7 character string only using a length of one.

Thanks for the help!!

 

[GaryS]

That makes sense 1 word 7 characters
each word can be 82 characters long
the len of a COP is words you are only copying 1 word
It's the way AB handles strings

 

[bernie_carlton]

Actually the COPy 'length' is number of the Target items you want to copy. So in this case it is number of strings you want to copy.