Hello,
I'm sorry if this is covered elsewhere. I read the App Note on using your own ethernet connector, and it made it clear we should reach out for help regardless of how well we think we know what we're doing. Which is good for me, because I'm not very confident and it gives me a fine excuse for looking stupid (not that I need one).My ultimate goal is to implement a 4-pin M12 d-pinout industrial ethernet connector instead of the RJ-45.
From the App Note:
- Appnote1.PNG (126.61 KiB) Viewed 4835 times
My first question is about hooking up VCC. Is this schematic saying that VCC comes from J3 on pins 3 and 6 and should simply be connected to the CT of the magnetics, or is it saying I should add additional feeds to the NB thru J3 and also feed it into the magnetics CT? My second question is in the depiction. This is from the spec sheet for the Halo product:
- HaloSpec.PNG (20.73 KiB) Viewed 4835 times
I'm asking this because I want to make sure I use my magnetics properly. The app note seems to suggest that the configuration of the transformers on the RX and TX side are 'inverted', if you will, while the spec on the Halo suggests that the oriention of the transformer pairs stays the same on both the RX and the TX side. Do you understand what I mean? If you call them Vertical or Horizontal, the Halo product shows VH, VH for both the TX and RX, The App note shows VH on the TX side, HV on the RX side. Which is correct?
For magnetics, I choose a Wurth Elec product, #749020100, which has the exact same attenuation per frequency band as the Halo product. But it shows this internal schematic:
- MAGS.PNG (28.43 KiB) Viewed 4835 times
It clearly doesn't have the internal resistors the Halo products shows, or the connection to the capacitor. But by the same token, I'm using the 4 pin M12 shown in the next picture. Phoenix Contact 1411975. How should I terminate the CTs of the cable end? I don't have a J4,5, etc. Do I need to add the resistors and capacitor?
- pheonix.PNG (44.76 KiB) Viewed 4835 times
This is the best depiction of the cable end I could find:
- EN_Pinout_M12-Dcode-20.gif (9.11 KiB) Viewed 4835 times
This is the current schematic, not knowing exactly which was I should connect the magnetics:
- enetschem1.PNG (13.98 KiB) Viewed 4835 times
I've clearly got a ways to go. Any advice or answers much appreciated.
Sincerely, Dan B.
