Hi, question for the HW side.
Curious why the choice to tie DGND to chassis Gnd on the board via R136? In most industrial environments this is likely to cause a ground loop between the DC Supply negative and earth ground for safety/noise shunting (Think DIN Rail 24Vdc or 5Vdc supplies grounded at the supply) and field devices as it will tie the chassis (earth ground) at the BBB and at the DIN rail power supply. As a side note, industrially the negative and earth are often isolated from each to avoid ground loops with sensor wiring.
I guess my real question to the group is what will I lose from the BBB certs/approvals/ESD performance if I remove R136 so I can isolate chassis ground and power ground back to a single point at the DIN rail power supply i.e. following a more traditional grounding scheme for industrial applications?
Alternately I can leave R136 and it’s likely under any notable load (sharing a ground with supply negative i.e. non-case isolated instruments etc.) it will go ohmic and open on it’s own when that load’s negative conductor bounces and the BBB becomes the return path to the DC Supply through R136/Chassis GND.