DP83822I: Inquiry about etherCAT design.

DEUGKI SHIN

Part Number: DP83822I
Other Parts Discussed in Thread: DP83869

Tool/software:

Hello.

I am currently designing an EtherCAT using the DP83822IH.

I am writing this to seek advice regarding EtherCAT design. To implement the minimum number of pins, I plan to use only 5 pins for the EtherCAT connection (TX +/-, RX +/-, Shield GND) with a separate connector instead of an RJ45.

After using a transformer, I am considering connecting the secondary side, which should originally connect to RJ45 pins 4, 5, 7, and 8, to GND or chassis GND. Would this be acceptable? I would appreciate your advice.

Thank you.

Best,

8 months ago

0 Gerome Cacho 8 months ago

TI__Mastermind 39855 points

Hello,

Essentially, you are asking if you may replace the secondary of the transformer with GND? This would not be recommended as our guidance has been to include Bob-Smith termination.

Sincerely,

Gerome

0 DEUGKI SHIN 8 months ago in reply to Gerome Cacho

Prodigy 50 points

Hello,

Thank you for your response.

I plan to use a separate 5-pin connector (TX_P, TX_N, RX_P, RX_N, Chassis GND) instead of a LAN connector as indicated below. Please advise if there are any adjustments or corrections that should be made.

Thank you.

Best,

0 Gerome Cacho 8 months ago in reply to DEUGKI SHIN

TI__Mastermind 39855 points

Hello,

Thank you for providing the diagram. I don't see any issues with this as the secondary of the transformer is connected appropriately. While slightly unconventional as we primarily expect RJ-45 connection, the 5 pin connector should be okay to proceed further.

Sincerely,

Gerome

0 DEUGKI SHIN 8 months ago in reply to Gerome Cacho

Prodigy 50 points

Hello,
Thank you for your response.

Lastly, I am trying to separate the primary-side and secondary-side grounds (GND). I believe that the Bob Smith Termination should be connected to the secondary-side GND, which is the chassis GND. Am I correct?

Best,

0 Gerome Cacho 8 months ago in reply to DEUGKI SHIN

TI__Mastermind 39855 points

Hello,

If there are separate GNDs, the bob-smith termination should be connected to Chassis GND. Our DP83869 MDI application diagram has a good example of such a case. Details are on footnote D.

Sincerely,

Gerome

Interface

Interface forum

DP83822I: Inquiry about etherCAT design.