Hi!
In DeltaV 11.3.1 I have an SFC in which I have inserted an ACT and a CALC block. My problem is that they do not get executed. The ACT's IN_D parameter is set to 1, GoodNonCascade, and the CALC block, of course, should run continuously.
Do you know how is it possible to run them?
Thanks,
Istvan
What for need you ACT and CALC in SFC? Transition is condition, step is ACTion.
If you really want use them, you can create new Control Module or in your SFC add "Embeded Composite" as "Function Block Diagram" and here insert ACT and CALC.
In reply to Roman Kostuniak:
I do not think you can add an embedded composite into an SFC. You can, however, add a linked composite or a function block.
But the problem is not adding them. They are already in, as you can see. But they are not running.
So, why is it possible to add them, if they are not running?
Roman Kostuniak said: What for need you ACT and CALC in SFC? Transition is condition, step is ACTion. If you really want use them, you can create new Control Module or in your SFC add "Embeded Composite" as "Function Block Diagram" and here insert ACT and CALC.
In reply to István Orbán:
Oh, I forgot to mention that this is an SFC composite which I am building.
Add a 'non-boolean, Stored' action & browse for the ACT/CALC block in the expression.
When this actin executes, the block will start execution.
You can reset this stored action in further sequence to stop execution of the ACT/CALC block.
Regards,
Amod.
Could you show me ACT/CALC expression? and control module print screen
In reply to Maarten van der Waal:
Amod, Maarten, thank you! This was the solution.
A small add to this which I found out later on. According to KBA NA-0500-0052, the ACT and CALC blocks should always run when not referenced by non-boolean actions, even when the SFC is in the state Stopped! This allows to reset/restart the SFC with the ACT block depending on some conditions.
Unfortunately this only works for SFC control modules, it does NOT work for composites, so the KBA is not correct. I have already opened a call about this and got the promise that the KBA will be updated with the correct info. If someone is interested in the investigation, look for call number NC-1303-0093.
Good patience man.... I checked your call with GSC.... :-)
Any way, I am lost why we have implemented this functionality in DV7.3 in the first place.... S-88 defines FBD as separate coding algorithm then SFC. The possibility to have the FBD inside SFC was only to execute any "supporting" parallel logic to the SFC sequence when active (e.g.: a continuous condition check with time delay (Press > SP for 10 sec, etc) is very hard to implement in our SFC algorithm capacities).
But in case "SFC controlling/monitoring" logic needs to run in parallel, structure similar to command driven EM or unit phase (FBD module with embedded SFC) is to be used. This keeps them on different level. Combining them to be able to start/stop the FBD inside the same FBD itself, will compromise S-88 hirarchy structure. When FBD is not running, it should not be executing anything...
Any way, this is just my thinking & I would advice against this way of configuration, irrespective of allowed by DeltaV or Not.
In reply to amodbobade:
Hi Amod,
Four this particular case the specifications asked for a transition returning to the first step of the SFC from a few dozen steps if a condition is fullfilled. We would have liked to solve this by an ACT block which monitors the condition, then stops/resets/starts the SFC so that we do not have to pull dozens of wires from these steps. Putting the ACT block outside the SFC composite (into the equipment module) was not preferred but we had to do it like that because of this.