Waveshare Dual ETH Quad RS485 Base Board (B) for Raspberry Pi Compute Module 4

My name is CM4-ETH-RS485-BASE-B, which is an expansion board that can be used with Raspberry Pi Compute Module 4, and supports a 7-36V DC power supply and 5V DC-DC power supply of Typc-C interface. Onboard four isolated RS485 interfaces, 100M+1000M dual network ports, HDMI interface, two CSI interfaces, two USB interfaces, etc…

Applications: 

Suitable For Raspberry Pi Applications Requiring Multi-Channel RS485 Communication Or Other Industrial Context

Features

• Do not plug and unplug any device except USB and HDMI when it is powered on
• Confirm the fan voltage before connecting, only support 5V
• The Type C interface can be used as a power supply or as a USB interface to burn the image (need to use the DIP switch to switch)
• In order to ensure the normal power supply of CM4, please do not connect other devices when using the Type C interface to burn the image.
• When CM4 is in normal use, it needs to provide a 5V 2A power supply for CM4. Otherwise, there may be problems such as automatic shutdown, frequency reduction, and so on.
• USB2.0 is closed by default, if you need to open it, you need to add dtoverlay=dwc2,dr_mode=host in config.txt

Useful link:

Waveshare Dual ETH Quad RS485 Base Board (B)