How to convert Ascii to a Number

[willer1998]

I am working on a problem with a scanner. The data comes in as ASCII. I am scanning the quantity. The data looks like Q1^M or Q21^M (They can have 1 or 2 digit quantity)
I need to tie in the qty with the machine to make sure it does not over produce or under produce. I cannot seem to convert the Ascii into an integer.
I am using SLC500. The data comes into a INTEGER file. I have tried copy, moving to ASCII, then to a STRING. And directly to a string. (Then I could use the ACI) But - nothing shows up in the STRING file. When I copy it I have to address it as ST9:0.DATA[0]
When you look at it in the ladder - it appears to have the value, but when you go to the data file - there is nothing.
When I copy the INTEGER file to the ST file - the ST file is 1330+ in length and when I try the AEX, I do not get any data.
Any suggestions?

 

[panic mode]

what are the HEX values of the characters you receive
and what is the value they represent? (^M should be 0x0D etc.)
is Q indicating start and ^M end of a string, meaning values are 1 and 21 etc.?

 

[harryting]

Can you see the number in the ST file?

The ^M should tell the PLC that's the end of the number. Make sure your COP is set for length of 1 only. COP #N7:50 #ST10:50 1

Once you got it into a sting file then use AEX to extract out the number. So if you have a number "^Q3^M", do AEX ST10:50 2 1. ST10:51.

After that, use ACI to covert ST10:51 to an interger. ACI ST10:51 N7:51

Oh, since your integer length varies. You need to find our the length of your string, ie, the value of ST10:50.LEN