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"SIMATIC Timers" versus "IEC Timers"

Thread Starter: hdhosseini   Started: 7/7/2013 10:19 AM   Replies: 31

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  7/7/2013, 10:19 AM
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Hello friends,

I suggest talking about cases we have encountered in practice and even in forum.I think in some issues we need to discuss."SIMATIC Timers" or "IEC Timers".What do you think about
  • Limitation we have in SIMATIC Timer (e.g number)
  • Easy in programming
  • Difficulty for data type handling for each cases and limitations for "SIMATIC Timer Data Type" (desmul24)
  • Execution Load on CPU in case of using several number of each cases
  • Memory consideration for IEC Timer when number increases
  • What characteristics of SIMATIC Timers are missed by IEC Timers "William B."
  • Inadvertent CPU stopping because of invalid Hex  time value for SIMATIC timers from HMI
  • Difference Dynamic behavior of IEC and SIMATIC Timers (IBN-Service) 
  • Working on your own timer in case of new features required and not included in both IEC and SIMATIC Timers (AMAZINGAHMED  and viralpatel )

Please, feel free to expand the list and write what you think based on your experience.All feedbacks are welcome.List will be updated by me or by your suggestions.

Thank in advance
Hamid Hosseini



=== Edited by hdhosseini @ 7/16/2013 12:34 AM [GMT ] ===
5) case in row #6 changed from "Limit range of type selection in IEC Timers" to "What charateristics of SIMATIC Timers are missed by IEC Timers" due to suggestion from "William B."

=== Edited by hdhosseini @ 7/16/2013 12:25 AM [GMT ] ===
4) Topic in row #3 modified due to impressive work of "desmul24"

=== Edited by hdhosseini @ 7/10/2013 4:22 PM [GMT ] ===
3) Thanks to "AMAZINGAHMED "and "viralpatel", new issue about "Writing Your Own Timers "added

=== Edited by hdhosseini @ 7/8/2013 2:03 PM [GMT ] ===
2) Make REVISIONS to transfer the question to the "STEP 7/ STEP 7 Lite" conference

=== Edited by hdhosseini @ 7/7/2013 6:39 PM [GMT ] ===
1) add first suggestion from IBN Service for dynamic behavior of both timers.

=== Edited by hdhosseini @ 7/7/2013 10:56 AM [GMT ] ===


=== Edited by hdhosseini @ 7/7/2013 10:48 AM [GMT ] ===


=== Edited by hdhosseini @ 7/7/2013 10:24 AM [GMT ] ===


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  7/7/2013, 11:07 AM
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puh, this little yellow minions make me addicted....
 

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=== Edited by IBN-Service @ 7/8/2013 7:12 PM [GMT ] ===



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  7/7/2013, 11:17 AM
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Beside those "little yellow minions" , I am sure, we can get result of this discussion here.



=== Edited by hdhosseini @ 7/8/2013 8:49 PM [GMT ] ===


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  7/7/2013, 11:23 AM
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OK.

blink

IEC Timers "waste" a datablock.
If you need a lot, you must organize them in a multiinstance call.

That IEC Timer needs memory is OK, but why we still have to declare a datablock???

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  7/7/2013, 11:26 AM
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Anoher thing that I dont like when using IEC Timer:
If I set reference time to 0, the timer will NOT start.
But a S5-Time will start without problem.

What I like at IEC Timer:
The reference Time is formated as "Time" in ms,
so it is very easy to calculate the time and display the value at HMI.

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  7/7/2013, 11:28 AM
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Every time I need a Timer in a FB,
I will always use IEC-Time, called as multiinstance.

But I take care, that I compare the setpoint (un)equal to zero in my code.

Mostly, if setpoint parameter is "Time = 0ms" I will disable the timerfunction in my function block.

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  7/7/2013, 6:52 PM
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Hello again,
I just re-phrase again the points mentioned by Jürgen :
  • If there is limitation of number of SIMATIC Timers, Time to use IEC timers.They cost memory.The  can be called with ordinary call of an FB and DB or in a more Multi-instance reusable structure.

  • For re-starting an IEC Timer, it is not possible to make the set point (Pre set Time) zero.This is common problem. and I just add a memory in parallel of input to make the re-start possible HERE.

  • Comparing "PT" in logic for being "zero" is necessary to gurantee troube free operation.

  • The output of IEC timers are in data type "TIME" and easy to process.


  • The missing point is "I tried to restart a SIMATIC On delay timer by making the time value zero", But no success.What type of SIMATIC timer you have tested for re-start?

Best regards
Hamid Hosseini



=== Edited by hdhosseini @ 7/18/2013 9:49 PM [GMT ] ===


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  7/9/2013, 10:30 AM
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Hello friends,

This is not an ordinary question.It is a discussion coming from Expert conference for new idea here.Please, only check the topics selected in the first post and write about that.Please do not write OFF-Topic.I will check all suggestions, provide feedback to moderators and also may add your experience as it valuable in 1st post.You can suggest new topics if you think, really relevant.

Best regards
Hamid Hosseini



=== Edited by hdhosseini @ 7/9/2013 10:36 AM [GMT ] ===


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  7/9/2013, 11:45 AM
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When I'm annoyed with the limitation of SIMATIC timers, I use another technique.
I use the cyclic OBs (e.g. OB32) and use its timebase to increment word or double word to achieve accurate timing.
I don't remember using IEC timer before.

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  7/9/2013, 3:21 PM
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Hi,
I want to add further opinion for above posts,

I mostly use CPU Clock memory as a time base then use it as per requirement as it support upto 100ms,
and for more accuracy using OB 30-38 series blocks

regards,

Viral patellaugh
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