The Waveshare RS485 to POE ETH (B) gateway is a TCP/IP to RTU Modbus communication gateway. Here's a guide to its operation.

Connections :

Configuration of the Waveshare RS485 to POE ETH (B) gateway :

To configure the gateway, you'll need the VirCom software, available from the manufacturer's website in the Resource Software section: https://www.waveshare.com/wiki/RS485_TO_POE_ETH_(B)#Operating_Steps


This is the page that should appear when you launch the software:

To access the list of gateways connected to the PC, simply click on the "Device" icon:

After clicking on the icon, a new window appears. Here it is:

If your gateway is connected via an RJ45 Ethernet cable to your PC, you should see your gateway appear in the list as above (if several Waveshare RS485 to POE ETH (B) gateways are connected to the PC, then all of them should appear in the list).


To access the gateway parameters, select it (it will appear in blue):

Then double-left-click on the selected gateway. This new window should appear:

The categories we're interested in are: Network, Serial and Advanced Settings.


In "Network" :

This is where we're going to set the "network / Ethernet" part of the gateway (editor's note: the IP parameters assigned to the gateway), which is connected to the master(s), i.e. the device(s) that give(s) orders to the other devices (the slaves) present on the network. In most cases, "IP Mode" should be set to "Static" and "Work Mode" to "TCP Server", as above.

The IP address to be entered in "IP Address" will depend on the network in which your devices are located; you need to set an IP address so that the gateway is also part of the network.

The "Net Mask" allows you to specify the maximum "size" (number of devices) of the network.

For example, with the parameters mit above ("IP Address": 192.168.11.15 with a "Net Mask": 255.255.255.0) this means that my network goes from IP address 192.168.11.1 to IP address 192.168.11.254.

For the "Port", this corresponds to the Modbus / TCP Port. It must be the same as the one configured in your network devices so that they can communicate with the gateway.


In "Serial" :

This is where we'll set the "serial / RTU communication" part of the gateway, which is connected to the slaves, i.e. those that receive orders from the master device(s) present in the network.

The "Baud Rate" is the speed of communication between devices, set in baud (usually 9600 or 115200). Note that if the distance between your devices is small, you can increase it to speed up communication. On the other hand, you should reduce it if the distance between your devices is great, as otherwise there could be a loss of information.

NB: It must be the same for all devices on your network.

For the other parameters ("Data Bits", "Parity", "Stop Bits" and "Flow Control"), leave them as above and make sure they match those set on your devices.


Finally, in "Advanced Settings" :

The three most important parameters are "Dest. Mode", "Transfer Protocol" and "HTTP Port". The other parameters should not be modified for simple, basic use.

In general, "Dest. Mode" to "Dynamic" and "Transfer Protocol" to "Modbus_TCP Protocol" for use with CRE Technology or other products.

"Http Port" must match the one set on your devices, and like "Port" in the "Network" section, it must be the same on all your devices (including the gateway).


You then need to modify a few parameters in "More Advanced Settings...", but to be sure that all the parameters modified so far are taken into account, click on "Modify Setting":

You should be back on the page with the list of gateways connected to your PC. Double-left-click on the gateway to return to the page for configuring its settings.

In the "Advanced Settings" section, click on "More Advanced Settings...". :

This new window should appear:

The only section where you need to make changes is "RS485 Multi-Host Support Settings":

In the "Modbus Gateway Type:" section, set the mode to "Simple Modbus TCP to RTU" to be 100% sure that Modbus TCP / IP to RTU communication will work perfectly afterwards.

Also check that the rest of the parameters are the same as on the images, then once this is done, click on "OK".

You'll be redirected to the previous page, where we made the initial settings.

Click on "Modify Setting" again:

You can now close the two remaining windows.


The gateway is now configured.