ControlLogix: Simple way to swap bytes of all words in an array?

Thought this would be a built in instruction but can only find SWAPB that only works on one word at a time.

File Fill
FLL

Source - the new value you want to insert
Dest - location of the first word ie. test[0]
Length - how many words

devo.xx said:

File Fill
FLL

Source - the new value you want to insert
Dest - location of the first word ie. test[0]
Length - how many words

Click to expand...

He wants to swap the bytes, with the data that is already there, not fill the data with something else.

I believe the instruction is only for one word at a time. Might be able to index through an array with a pointer. Never had a need to do because most of the time the issue is due to an HMI, and most HMI's have the ability to swap on their end.

James

Make a for/next loop with JMP/LBL pairs.

I was trying to think of a way to make FAL work. If you copied it to a SINT array with a file COPy, and then used the expression A XOR (B XOR(A XOR B)) (bit hack for a byte swap) and then copied it back to the DINT array so you had whole words you could probably get it to work. But with all the copying I think a for/next loop is the way to go for a large array. For a small array just brute force it, its simpler.

what the different on this example with the OP request ?


RSLogix 5000\Projects\Samples folder, Swap_Bytes_in_Array.ACD file.

osmanmom said:

what the different on this example with the OP request ?


RSLogix 5000\Projects\Samples folder, Swap_Bytes_in_Array.ACD file.

Click to expand...

I think that is what he is needing. Thanks for posting.

James