Just thought I would supply an example. The string I am reading in looks like this: 0184191A001C In the real world, this is a HEX code It is ASCII (String) once in the ControlLogix. I need to break the string into this: 01 84 19 1A 00 1C I need to convert each 2 digits to HEX and add them together, appending the sum to the end of the orginial string, and send it all back out again. Remember, although the string is coming into the PLC as ASCII, they represent HEX numbers.