how to be a Professional Siemens PLC STL programmer

[Clay B.]

you lazy, didn comment to everyone not as good as you

     L     L#0 //long dec 0 ->accu1
      L     #N  //accu1 -> accu2 #N ->accu1
T:    TAK       //accu1 -> accu2, accu2 -> accu1 
      +D        //accu1 + accu2, accu2 unchanged result to accu1
      TAK       //accu1 -> accu2, accu2 -> accu1
      LOOP  T   //decrement accu1 by one, jump to T
      TAK       //accu1 -> accu2, accu2 -> accu1
      T     #RET_VAL  //accu1 to ret_val

LMAO..the code with comments looks just as cryptic as the non commented version...

 

[TurpoUrpo]

yeah, well but as ld said, it is not really "commented", its instructions written to as comments.

then on the other hand after you have learned what that means, it is much easier to proceed.

accus are something that lad/fbd programmer will never even bumb into with siemens. but then, you miss lot of its power.

 

[Clay B.]

yeah, well but as ld said, it is not really "commented", its instructions written to as comments.

then on the other hand after you have learned what that means, it is much easier to proceed.

accus are something that lad/fbd programmer will never even bumb into with siemens. but then, you miss lot of its power.

I agree completely. STL lets you do so many things you can not do with ladder and it is definatly something to learn if you want the full power of an S7-300 or S7-400.

Just make sure you have lots of time to devote to it. It is definnatly not a language for the weak at heart.

My suggestion and it is something I do is write in STL and try to convert to ladder. Do simple things like OR's, AND's etc...

Once you get that break out a manual and look up a function. Play with it until you get it and move to the next one. THis has helped me understand alot.

 

[manmeetvirdi]

      L     L#0
      L     #N
T:    TAK   
      +D    
      TAK   
      LOOP  T
      TAK   
      T     #RET_VAL

OK LD on paper this works, but on PLC it doesn't !!

 

[L D[AR2P#0.0]]

Which plc ? i tested this in a 317-2DP. Doesn't work in the simulator though as it executes with 4 accumulators.

 

[manmeetvirdi]

Wow !!
I checked in PLCSIM using 317-2PN/DP.
But it should work as code is using only acc1 and acc2.

 

[TurpoUrpo]

Look at instruction TAK differences with 2 and 4 accu cpus..

 

[L D[AR2P#0.0]]

From plcsim help:

 

[manmeetvirdi]

Ah !
One of those rare but important differences.

 

[L D[AR2P#0.0]]

..

 

[L D[AR2P#0.0]]

Ah !
One of those rare but important differences.

... so which one is the Professional Siemens PLC STL programmer ?

 

[mordred]

The one with the biggest ears you can tell cuz the other one is looking up at him

 

[manmeetvirdi]

... so which one is the Professional Siemens PLC STL programmer ?

Its YOU Sir.

 

[allscott]

I agree completely. STL lets you do so many things you can not do with ladder and it is definatly something to learn if you want the full power of an S7-300 or S7-400.

Just make sure you have lots of time to devote to it. It is definnatly not a language for the weak at heart.

My suggestion and it is something I do is write in STL and try to convert to ladder. Do simple things like OR's, AND's etc...

Once you get that break out a manual and look up a function. Play with it until you get it and move to the next one. THis has helped me understand alot.

Any examples of what you can do with stl that you can't do in ladder?

 

[leitmotif]

... so which one is the Professional Siemens PLC STL programmer ?

The one that gets paid.

Dan Bentler