Hello. I am an engineer involved in electronics development. There is a need to install a GigaBlox Nano switch and an RTL8213B media converter on the board. The communication between the controllers is capacitive. Four pairs are connected. The controllers only set the speed to 100M. 1000M does not work in any way. Separately, the RTL8213B and GigaBlox Nano are connected to sources with transformer isolation at 1000M speed. I tried a separate optical converter with a transformer also on the RTL8213B chip, it does not connect at 1000M speed, only 100M. Power and ground are clean, conductors are short, and differential pair routing is also done. What could be the reason? 1000M speed operation is needed. Thank you in advance for your response.
I’m struggling to understand your setup here so I will first attempt to summarise your system and ask questions as I go.
The communication between the controllers is capacitive. Four pairs are connected
- What are these “controllers”?
- When you say they are capacitively coupled, do you mean they connect directly to GigaBlox Nano (GigaBlox Nano already has capacitors onboard)?
The controllers only set the speed to 100M
- Do you mean these controllers turn off autonegotiation and set their port speed to be fixed at 100M? How do they do that, do you log into the controllers to achieve that?
1000M does not work in any way
- Are you expecting this? If you connect a fixed 100M port to GigaBlox Nano, the connection would be expected to be 100Mbps.
Separately, the RTL8213B and GigaBlox Nano are connected to sources with transformer isolation at 1000M speed
- This is quite unclear, can you clarify the connections here. How is this all connected? Is it RTL8213 ↔ GigaBlox Nano ↔ Transformers ↔ Sources?
I tried a separate optical converter with a transformer also on the RTL8213B chip, it does not connect at 1000M speed, only 100M.
- How do you wire the optical converter to the RTL8213B chip? Is it an SFP module?
Power and ground are clean
- I assume you measured this with an oscilloscope?
I think it would help a lot if you draw a picture.
I mean that the GigaBlox Nano switch is connected to the RTL8213B-CG (10/100/1000M Copper to 100Base-FX/1000Base-X Fiber Media Converter) via isolation capacitors on the GigaBlox Nano. The RTL8213B-CG is soldered onto my board, and an SFP module is used with it. When connecting this Media Converter to any network device (devices with transformer isolation), it operates well at 1000M speed. However, the GigaBlox Nano does not want to operate at 1000M speed with the RTL8213B-CG chip. Additionally, I connected to the GigaBlox Nano, separately from my circuit, a ready-made device - a Media Converter with an SFP module on the same RTL8213B-CG chip and with built-in transformer isolation. The result of the connection is only 100M; it does not connect at 1000M speed. The influence of my board is excluded; a ready-made board is used - GigaNano PicoConn Rev. A with RJ45 connectors at the ends. I don’t know which way to think. Is it possible that the RTL8213B-CG and RTL8367N-VB-CG, installed in the GigaBlox Nano, have incompatibility at 1000M speed? The power supply for RTL8213B-CG and RTL8367N-VB-CG is clean, 12V, with minimal pulsations, and there are no power lines on the board and no ground interference, respectively.
Thanks for the clarification.
If you’re using it with a ready-made device then it should “just work”. It could be that you need the transformers between the two chips. Does the “ready-made” board contain transformers on board? Feel free to share the part number for that.
Do you have a GigaBlox Nano RJConn you can test this with? RJConn contains transformers.