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Using 4DIAC in a simulation system [message #1839641]

Thu, 25 March 2021 01:28

Neil Higgins

Messages: 18
Registered: September 2016
Location: Brisbane

Junior Member

I have an interesting proof-of-concept task for a power system controller. The controller would be implemented in IEC 61499, would export control commands to a power system simulator, and would import power system measurements from the power system simulator to complete the loop. The simulator has a COM API, somewhat dated, and some massaging of identifiers and values would be needed to map them between the simulator and the IEC 61499 environment.

For testing purposes, the IEC 61499 side would have to work in non-real-time, i.e. pause to await an update of the simulated power system quantities before proceeding. Because the power system simulator also has time-managed simulation capabilities, a common "simulated time" clock and (perhaps) a federated event queue would be desirable.

1. I assume that FORTE currently uses Linux time services in real-time(?) Is there an intervention mechanism, e.g. to substitute a different "clock" which would appropriately affect event and time management in FORTE? If not, does anyone want to provide hints as to which parts of the source code I should look at?

2. As mentioned in another post, I am looking at MQTT as the IPC mechanism between the power system simulator and FORTE, although this would be crude and less-than-ideal. Access to the Lua code for one or more dynamic types would provide a much more flexible alternative. Is there some way that this might be enabled?

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Re: Using 4DIAC in a simulation system [message #1839655 is a reply to message #1839641]

Thu, 25 March 2021 09:27

Jose Maria Jesus Cabral Lassalle

Messages: 16
Registered: January 2021

Junior Member

I have worked with FMI, a standard simulation https://www.eclipse.org/4diac/en_help.php?helppage=html/communication/simulation.html#fmi

I basically extended the CEventChainExecutionThread class with my own (CFMUEventChainExecutionThread). This class handles the event triggering.

The CFMUEventChainExecutionThread class has a semaphore that can pause/resume it, and this pause/resume is controlled by the src/core/fmi/fmiTimerHandler.cpp:advancedTicks function. This function is called externally by means proper to the FMI standard. In this case, the advacenTicks function is implemented so it can run the CFMUEventChainExecutionThread threads for defined amount of time.

Maybe this would help you, and if your power source model can be exported as an FMU instance, then exporting your 4diac application as FMU will allow you to co-simulate them easily. That's the main idea of the FMI standard

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Re: Using 4DIAC in a simulation system [message #1839665 is a reply to message #1839655]

Thu, 25 March 2021 11:18

Neil Higgins

Messages: 18
Registered: September 2016
Location: Brisbane

Junior Member

Dear Jose,
Thank you for your quick reply. I will do further research on this option.
Kind regards,
Neil

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Re: Using 4DIAC in a simulation system [message #1839701 is a reply to message #1839641]

Fri, 26 March 2021 01:10

Neil Higgins

Messages: 18
Registered: September 2016
Location: Brisbane

Junior Member

BTW I am aware that Thomas Strasser has produced a number of publications on this general topic. I will of course be collecting these and reading them.

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