Sequence instruction for S7 and positioning

[WilsonNC]

Is there a sequencer instruction for S7, or does anyone have a function for one. I want to index a pointer into a DB of 20 DINT's. The outputed value will then be added and subtracted with another "window" value. The new value will be compared to the DINT value coming from a POS338 module. Sort of a crude position method, but it works fine with AB logic.

Does anyone have any ideas on the easiest way to accomplish this?

 

[504bloke]

Interesting read here

http://www.plctalk.net/qanda/showthread.php?t=45009&highlight=S7+sequencer

http://www.automation.siemens.com/m.../en/step7/simatic-s7-graph/Pages/Default.aspx

 

[L D[AR2P#0.0]]

Example function to return the indexed value from an array of DINTs shown in the attached project.

 

[TurpoUrpo]

Peter made whole library of index blocks for s7.

 

[Peter Nachtwey]

TurboUrpo's link didn't work
http://www.deltamotion.com/peter/S7/S7ug.zip
It should be easy enough to use the index routines to load from the array into temporary variables, do the math and then use the index routines to store the result.

 

[TurpoUrpo]

My link works for me.

 

[L D[AR2P#0.0]]

.. and me..