Cycle time exceeded

You need new algorithms to perform the various matrix functions over multiple PLC scans instead of a single scan.

If you need all this work performed every single scan, you are using the wrong hardware platform. 

sajjad allahgholi

Hello

My program contains several loops that when i want to download it to plc , plc go to stop .i checked cycle time and sure that problem caused by "cycle time exceeded".is there way to fix this problem?

In the simplest terms, convert something like this:

FOR #b_i := 0 TO 99 DO
  IF #lsb THEN
    ; // do something
  ELSIF #aBufferInUse THEN
    ; // do something else
  ELSE
    ; // otherwise do this
  END_IF;
END_FOR;

to this: 

IF NOT #loop_completed AND (#loop_count < #loop_end) THEN
  IF #lsb THEN
    ; // do something
  ELSIF #aBufferInUse THEN
    ; // do something else
  ELSE
    ; // otherwise do this
  END_IF;
  #loop_count := #loop_count + 1;
ELSIF #loop_count > #loop_end THEN
  #loop_count := 0;
  #loop_completed := true;
END_IF;

Your algorithms do not lend themselves to being broken open like this. You may want to consider breaking your calculations into smaller pieces, or using different methods or algorithms entirely that work on real-time devices like PLCs.

You can also use a more advanced HMI and put the heavy script load on the HMI provided the results are not time critical.

How often are these calculations required?  Once every minute?  Once a second?  Once a day?

You may also want to look at the algorithms used by the OSCAT open source matrix math functions that may already solve some of the problems, keeping a plc scan in mind.

sajjad allahgholi

huggy_d1

You need new algorithms to perform the various matrix functions over multiple PLC scans instead of a single scan.

If you need all this work performed every single scan, you are using the wrong hardware platform. 

sajjad allahgholi

Hello

My program contains several loops that when i want to download it to plc , plc go to stop .i checked cycle time and sure that problem caused by "cycle time exceeded".is there way to fix this problem?

 

 Excuse me how to use multiple PLC scans?

Another option at your disposal is to perform a portion of the entire calculation each scan, but not the entire thing.

The Matlab generated function blocks are not very Siemens specific.

Siemens has a set of matrix operation function blocks you can use.

See this reference:

https://cache.industry.siemens.com/dl/files/674/29851674/att_12450/v1/29851674_operationen_bausteine_v10_e.pdf

https://support.industry.siemens.com/cs/document/29851674