This little serial server is a well-built, no-nonsense device that does exactly what it claims to do. Sure, the setup process may not be for the faint of heart, but it's genuinely well-documented on the Waveshare Wiki. You just have to run one piece of software from the wiki article, and you'll be set.
But first off, the construction is nice and robust. The aluminum enclosure is welcome, and the rail mount makes it that much more convenient. The one minor build quality issue I faced was that the green "Active" LED seems to be slightly misaligned somehow. If you look at it from a certain angle, you can see it blinking green. But only from a certain angle, because I guess it's not lined up with the hole and diffuser. But I can excuse that, personally. That's literally the only "fault" I found with this device.
I really like that it's easy to power. Through PoE, through a barrel jack (accepting 6-36V; I gave it 12V and it was happy), or through the plus and minus screw terminals (which also accept 6-36V). Pretty convenient, even if it doesn't come with a power cable/adapter out of the box.
In my testing, I was able to get a simple RS232 echo server running. For the sake of posterity, here's what I did to get it to work. Admittedly, some of this stuff is a bit esoteric, but it should be pretty familiar to anybody who's worked with serial ports before. And I'm on Manjaro Linux, so some things are a bit different, but I was able to get it to work.
First off, I connected 12V DC via the barrel jack, and plugged the Ethernet jack into my router. I couldn't find or connect to the device yet, but I was able to use the "VarCom" software that can be downloaded from the Waveshare website. It's Windows-only, and requires MFC42.dll, but I was able to get it to run with Winetricks. And once it started it was happy.
From VarCom, I click on the Device Manager button, and found the server as "192.168.1.200". I was then able to reconfigure it to an address in my router's subnet, and saved the changes. There are pictures of this process on the wiki, you'll know what I mean when you see it.
I then visited the new IP of the server in my browser, and was greeted with the web interface. That's when I knew it was working. From then on, the setup was a breeze (and to be fair the process so far is probably a bit easier on Windows).
I then did ran a command like this, to bind port 4196 of the server (where the actual TCP serial server was running) to a virtual serial port in Linux. There are probably better ways of doing this, but it worked just fine for testing:
sudo socat pty,link=/dev/waveshare,raw tcp:192.168.xx.xxx:4196&
(where 192.168.xx.xxx is the IP of my serial server, and /dev/waveshare was what I decided to call the virtual serial port. The & at the end of the command means it keeps running in the background, letting me use that terminal window for something else).
Then, I connected a USB to RS232 adapter cable to my computer (with a DB9 port on the other end). And I plugged the DB9 port into the serial server.
Finally, I opened a minicom session with:
sudo minicom -p /dev/waveshare -b 115200
And another session in another terminal window, to connect to my USB serial adapter):
sudo minicom -p /dev/ttyUSB0 -b 115200
From there, I enabled local echo in both terminals, and set it so they'd send each other line feeds. And just like that, I was able to type in one terminal and see the output on the other, and vice versa.
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I have some actual use cases in mind for this device, one of which may make use of the RS422 capability. But for the purposes of this review, I think my RS232 test was sufficient. It was honestly a lot of fun, once I figured out what was going on. While it requires a weird Windows-only program to initially configure it, I won't hold that against this product. Because once it's up and running, it's basically magic. Makes me wonder if they make a version with WiFi; that would be cool.
But I think you're getting good bang for your buck with this thing. It's solid and dependable, and "just works" without having to fight with it. And the versatility of the power and connectivity options is basically unparalleled. So it's a definite 5 stars in my book, even if I'm only scratching the surface of what it's capable of.
| RAM | DDR4 |
|---|---|
| Memory Speed | 300 MHz |
| Wireless Standard | 802.11b |
| Brand | Waveshare |
| Series | Industrial Serial Server |
| Item model number | RS232/485/422 TO POE ETH Converter(B) |
| Operating System | Linux |
| Parcel Dimensions | 10.9 x 8 x 3.1 cm; 150 g |
| Processor Brand | waveshare |
| Number of Processors | 1 |
