cRIO 9074 Error -2147138533 on scan engine transition to active

[Omar_Mussa]

I have a cRIO 9074 configured as an EtherCAT master.  The FPGA code for this RIO is monitoring other status data and it is capable of shutting down power to the rest of the system (including EtherCAT Slaves) as a safety feature.  If I power cycle the cRIO (which trips power to the EtherCAT slaves) I get the following error when transitioning back to active mode on the scan engine:

Error -2147138533 occurred at Property Node (arg 1) in Set Scan Engine Mode.vi->RT System Startup.vi

Possible reason(s):

The telegram times out.

Check to see that the master device is connected to the EtherCAT network. Ensure each slave device in the EtherCAT network is powered on and properly connected.

Is it possible to start the scan engine even with the slaves powered off?  Do I just need to change my program to dynamically discover slaves to stop the scan engine from faulting on scan engine transitions?  I don't want to power my EtherCAT slaves back on until I can read data that is currently being monitored via the scan engine on the same RIO ... is this possible somehow?

[tcap · Accepted solution]

Hello,

EtherCAT is tightly coupled with the Scan Engine.  There is no way to set the Scan Engine to Active, while an EtherCAT Slave is disconnected.

I recommend looking at the following KnowledgeBased Article to Programmatically Discover and Access EtherCAT.

http://digital.ni.com/public.nsf/allkb/FDC87938F1191A3C862578FF00757270

Regards,

[Omar_Mussa]

That is helpful.  I think that my other option is to move the IO monitoring of the safety IO that is used to determine if it is safe to enable the EtherCAT/Scan Engine into the FPGA code - that way I can manually monitor those IO points and when ready, enable power to the EtherCat Slaves and then transition the scan engine back to active mode.  Does that sound right?

[tcap]

Hello,

That should definitely work, depending on how you architect it.  You might want to read a little more on Hybrid Mode, before starting to build your application.

http://digital.ni.com/public.nsf/allkb/0DB7FEF37C26AF85862575C400531690

Regards,