Example of the STRING_TO_x block in FBD using Control Expert (formerly Unity Pro ) .

Goals and Symptoms

This resolution is intended to outline the operation of the STRING_TO_x blocks from Control Expert (formerly Unity Pro) instruction set

Causes and Fixes

The STRING_TO_x blocks will convert strings of ASCII decimal characters stored in multiple contiguous registers into one tag.
The Unity Pro instruction set has three blocks
STRING_TO_INT
STRING_TO_DINT
STRING_TO_REAL
For this application, we will use the INT version.

Two tags are created:
String_In of type STRING located at %MW1 and
Int_Out type INT located at %MW100.

String_In occupies %MW1-%MW3
Each byte of the memory words contain one ASCII decimal character. These ASCII decimal characters are converted into one integer value containing the integer equivalents located at %MW100.

If the String_In is pulled up in the animation table you will see something like the example below:



If the three occupied %M's are pulled up in the animation table you will see the individual characters; two ASCII decimal characters per %MW:


The converted string is shown below both by pulling the tag and the %MW location itself: