EtherCAT chassis delayed Power Up causes Scan Engine to drop into Configuration Mode

[Thoric]

I have an NI 9024 controller on a 9114 chassis plus an EtherCAT 9144 expansion chassis.

For complicated reasons, the EtherCAT chassis will be powered up several seconds after the 9114 chassis.

During testing, when both chassis were powered up together, all has been sweet. But with the staggered power up routine in place, the Scan Engine drops straight into Configuration mode, which results in no data communications from the EtherCAT device.

I expected the system to cope with a delayed power up of the EtherCAT device by denying access to the Shared Variables for the expansion chassis modules until they were available. I know I can programmatically alter the Scan Engine mode, but I don't want to have to do this if I can help it.

So, my questions are:

Can anyone tell me why the Scan Engine will revert to Configuration mode if an expected EtherCAT chassis is not present at power up?

What is the minimum delay between powering up the two chassis to establish a successful connection?

Thanks

[Ashish_Naik_NIUK]

Hi Thoric,

Thanks for posting on the forums!

I am unsure on the exact minimum time delay you could use for startup.. The reason the device goes into Configuration mode is simply due to the device not matching the IO it finds to what it expects, hence why it goes into config mode. (Figure 8 of http://zone.ni.com/devzone/cda/tut/p/id/10555

The only way around I can think of is to programmatically set the mode, which you mentioned you knew how to do.. 

Thanks,

Hi Thoric,
Thanks for posting on the forums!

I am unsure on the exact minimum time delay you could use for startup.. The reason the device goes into Configuration mode is simply due to the device not matching the IO it finds to what it expects, hence why it goes into config mode. (Figure 8 of Getting Started with EtherCAT on NI Programmable Automation Controllers )

The only way around I can think of is to programmatically set the mode, which you mentioned you knew how to do.. 
Thanks,

[Thoric]

Hi Ashish,

Thanks for the info. I will just have to use the programmatic method for switching the Scan Engine mode then, although I was hoping to avoid this.

Many thanks for replying!

Regards,