Thunderstorm

Hello Eli_47,

PCS 7 optimzes the processing and cycle sequence very good.

But it is a machine.

It is better to think about the sequences by your own.

Consider also the different OB times.

Selecting an optimum sampling time of PID controllers

Hi SilentBob,

That was a helpful answer.  I'm wondering though if the system requires a download to take the changes of moving execution ordering around in the run sequence.  Thanks.

Hi roseautomation,

you can optimizing runtime groups while the PLC is running. Offline you can click on "Optimize Runtime Sequence..." after that you can compile and download the changes without stopping the CPU or PLC.

Silent Bob

Hi.

In the projects where I worked on it was forbidden to use the automatically optimization of runtime groups.


Optimizing runtime groups can fix your randomly placed blocks very well IF you have a straigt logic and signal line.

PCS 7 is optimizing runtime groups by the way of the signal. If you have a block (B1)that has its output connected to an other blocks (B2)inputbut B2 is in the runtime group before B1, PCS 7 will place B1 before B2.

But pay attention:
In some logics you don't have such easy constellations. There might be constellations where it is important that the position of some blocks are switched (e.g. to have a value from the last program cycle).
If you now optimize the runtime groups with this function, your program won't work any longer.

So my recommendation to you is:
Pay attetion to the sequence of the blocks when you create your CFC charts. Its not a lot of work. If you have many blocks in a chart you can start randomly. But when you are done with you connections open the runtime group editor and place the blocks in a correct manner.

If you want to use this function you also have the posibility to exclude individual runtime groups from beeing optimized.


so long...

 This is stupid, because such things as the value of the last cycle must be formed in separate blocks. 
In normal projects with proper quality control, you get a slap on the wrist for this if you create a software delay by the order of blocks in cfc.
The optimization tool is very good and helps to avoid and optimize execution time. When I give an example, the program ran for 120ms after optimization for 30ms, so this tool is needed, but in order to use it, you need to prepare the correct software to use it.