waveshare Ethernet Industrial Serial Server RS485 to RJ45 Ethernet Module, TCP/IP to Serial, Support Rail-Mount/Modbus Gateway, TCP Server/TCP Client/UDP Mode/UDP Multicast Multi Communication Modes

I'm working on a personal project with the Modbus functionality. The device I'm working on was tested with the Serial to RS485 dongle and working fine. I added the RS485 to the RJ45 Ethernet Module (waveshare), enabled the Modbus TCP to RTU mode, set the device address, and sent the following command: `modbus 192.168.6.35:2020 -s213 h@13` The "waveshare" is able to transmit data to my device, and my device successfully processes the command responding with the correct Modbus response: [23:50:09][D][uart_debug:114]: <<< D5:03:00:0D:00:01:07:DD [23:50:09][D][uart_debug:114]: >>> D5:03:02:08:27:CF:8C However, the "waveshare" device, seems, to either have a defective RX port or can not transmit the response back. I tried modbus_cli and ModbusMechanics. Both fail with the "waveshare" device but work with the USB458 dongle. *Correction*: Looks like it was a subtle bug with the particular Modbus library on my device and/or the device(s). Even though the USB dongle works correctly, another device from a different vendor behaves the same way. Setting 2 stop bits helped. I assume the "waveshare" device would work perfectly with this setup. Sorry for the initial negative review.

We have some devices using MODBUS-RTU and have employed these to remotely monitor those devices across our network to the NOC via MODBUS-TCP as a basic gateway. They are compact and easily configured, but lack TLS or any other network security that some networks may require.

Works great. The web UI is good, so dip switches are required to change baud rate, and you can do all sorts of configuration with the config page. The default addr is 192.168.1.254, it was unfortunate the same as my gateway, so I had to hard wire to it to change the IP address. Other than that, it is very easy to use. I hooked up a thermostat and humidity sensor to it and created an IOT app.

Allows comms in one direction, no issue.

Immediately there's one problem, and I don't understand why Chinese manufacturers do this: The IP address is set statically at 192.168.1.254 rather than using DHCP. Even when set to DHCP, it does not properly pull DNS servers from DHCP and has it set statically to 192.168.1.3, which doesn't matter much because it doesn't need DNS, but still. It's such a weird default that the rest of the world does not use. Ethernet devices should start with DHCP, and they should always pull DNS from DHCP unless set statically after DHCP config. After that, everything is excellent. Just beware that the ground plug on top of this is not the same as the negative of the input voltage. Make sure your modbus sensor/device is powered the same way this is powered. Honestly, a great device and exactly what I needed for testing a modbus TCP implementation.