Details about swap board connections for Jetson AGX Xavier

I’m a newbie in electronics and I’m trying to connect two agx developer kits, one of them is RC and the other is EP.
We’ve made the swap board by referring to the guide document.(Jetson_AGX_Xavier_Series_PCIe_Endpoint_Design_Guidelines_DA-09357-001_v1.3.pdf)

Meanwhile, we read the warning sentence

Note: If the two Jetson AGX Xavier devices shown in Figure 1 are on separate systems, then the power rails should not be connected between the two. The grounds for each system should be connected.

Q1. I’m not sure what it means that ‘power rails should not be connected’. If you don’t mind could be give me a detaild explanation with example?

Q2. We connected GND of all 4 ODs to RC side B4 (ground), please let us know if it is right.

Thank you.

That has been answered in the note of figure 3 as below:

Note: The power rails are not connected since both the Root Port and Endpoint systems will provide power to their respective PCIe connectors. This will avoid possible issues with power being applied by the first system to power-up to pins in the other system that has not yet been powered up.

Thanks Turmany,
How about my second question?
All OD’s GNDs are connected to root port’s side B4, is ok?

Please refer to the E3317 schematic which is attached in the guideline doc.

Excuse me, I’m novice.
If all OD’s GND are connected to B4 which is on RC port side, is okay?
EP should be booted first, and then RC should be booted.

And I have one moe question.
When press power button, AGX’s white power LED tuned on by H/W or S/W ?

Have you checked the schematic of E3317 in the guide doc? Please follow that to make GND connection.
Which LED do you mean? Please tell the part number of it or you can check the P2597 schematic in DLC to find out the answer.

It’s a white colored LED that you can see outside on AGX’s frontview. It is on the right from the 40-pin expansion header. I guess the partnumber is DS2.