SIMATIC S7-1200

How to address byte inside a string

Erstellt von simaticfan79 am 15.04.2012 16:46 (2 Antworten)

  15.04.2012, 16:46

simaticfan79 Beigetreten am: 04.01.2011 Letzter Besuch: 30.05.2013 Beiträge: 20 Bewertung:  (0)

(0)  Dear colleagues, I have this problem... I want to address byte inside a string but I find it imposible with TIA portal V11 SP2. I create standard DB (S7300 compatible) and inside DB I create string. For example: "TESTDB".TSTRING[32] But If I want to address byte inside that string in SCL or LAD editor with absolute addressing for example: DB7.DBB6 it changes immediately into "TESTDB".TSTRING and so It is impossible to address byte inside a string. What I am doing wrong? Thank You!

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  15.04.2012, 20:54

jklm Beigetreten am: 22.12.2006 Letzter Besuch: 09.06.2013 Beiträge: 1296 Bewertung:  (151)

(0)  Hello, There are several solutions.  Here a less known possibility. In SCL there is a special instruction AT that allows to define the same data but with another format. As in the small example in annex (not tested on a real PLC, and to be adapted to your needs). The FC gets a char (aChar) inside a String (InString) at a given position (POS). The temporary variable TempString and TempStringChar occupy in fact the same area. Allowing to access the data as desired. Dateianhang: CharInString.pdf  (60 Downloads) === Edited by jklm @ 4/15/2012 8:58 PM [GMT ] === Best regards jklm Suggestion was helpful? Thanks to rate it.

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  15.04.2012, 22:44

simaticfan79 Beigetreten am: 04.01.2011 Letzter Besuch: 30.05.2013 Beiträge: 20 Bewertung:  (0)	(0)  Thank You jklm for your answer! I've learnt something new!
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