As part of one new requirement for web application I am maintaining, we need to send a signal to a device in a factory when certain conditions are met in the application.

Sending a signal is simply short-circuiting 2 wires (physical push button). The controlled device is not anywhere near the web server that is hosting application, but it is on the same network. S the idea is to buy boards that already have hardware relays and can accept activation commands via TCP/IP. The ability to secure a board with password protection is a plus but not a must.

As one of goals is to have as much standard interfaces as possible. We would like to avoid making our own Arduino- or Raspberry- based boards. I am asking if there are some known and simple industry-grade relays/switches with a TCP/IP interface?

Is there a name for such device?

I tried to search for it and closest I found is this Chinese board that allows steering 2 relays through TCP/IP.

This seems like a long shot to ask here but I am hoping someone worked with similar devices and it would be great if I can get a name of a reputable company that produces such devices.

  • Another option is to have a standard PC (something low power or even a Pi to accept the TCP call and then connect your relay via USB to that PC). You could do this over WiFi using ESP8266. I've designed a similar solution for a lamp. The only difference you have is the rating of the relay. I know you said you didn't want to build a board, but this could be done in an afternoon. This was actually part of a project I did with some 9 year old kids.
    – Gineer
    Commented Jun 13, 2017 at 8:35
  • What do you mean by "Sending a signal is simply short-circuiting 2 wires"? That makes a crucial difference on equipment needed. Some of the provided solutions may be overly heavy if you play with some 12VDC but if you play with 230VAC or higher maybe none of them suits. "Simply short circuiting" may refer to anything.
    – mico
    Commented Jun 14, 2017 at 5:36
  • You are correct, but that is piece of information I still do not have (equipment is on another continent). I know this is not something that powers the machine, just sends the signal (so max 1A, and 220V or less). Possibly 12V DC but I cannot confirm yet. Commented Jun 14, 2017 at 6:34

5 Answers 5


There are a lot of devices out there that allow you to control digital I/O over a network. The difference between this and relay control is very little as you can very easily add a Solid State Relay to a digital output.

Products in this space can vary from hobbyist to home to industrial.

When selecting, there are some other things you should consider when using these in a business environment.

  • Does the item integrate well into my company's network (is it just static IP, does it do DHCP, DNS, etc.). Will your IT department allow it on their network.
  • How remotely do you need to access it (just within the LAN or WAN or internet).
  • Are there any safety concerns regarding the remote activation? Turning on a 5V LED is a lot lower concern than turning on an 110V AC light. What if someone was servicing it and it was turned on remotely?
  • Yes, at work we have a formal ECP and I am glad that eWon's products are designed with safety in mind. I just wanted to make sure others who hadn't been exposed to the idea thought about it. That is why I posed it as a question. Commented Jun 18, 2017 at 18:36
  • Thanks! This is very good answer, and I am very tempted to use this WebRelay device over eWON, because they are cheaper, and I don't need any of additional eWON features (this is just a signal to replace a taster pressed manually to tell machine something was done - machine is secured and turned on/off elsewhere). I am also having hard time to decide which of 2 answers (this and one by @McDonald's) to award with bounty, as honestly you both deserve it. Commented Jun 18, 2017 at 19:15

Industrial Grade and Easily Scalable

If you want an industry grade device that's not targeted to be sold to home/private customers, then check out the eWon products. In particular I can vouch for the Flexy models scaling from 10 or 100 data points and/or IO mappings, etc. There is more than just the Flexy though so check out their other products from their Product Gallery that may be even better suited for your need.

Secure and TCP/IP Network Accessible

You can connect to these things via a secure SSL HTTPS web interface, via a VPN client connection, or make URL API calls to return data or push data to trigger an ON or OFF for instance. I'm sure there's functionality I've not fully discovered with these things still but they work well and seem to fit the criteria you ask in your question.

You configure your device for access to a data network via Ethernet or wi-fi, and these other methods of communication as listed on eWON Flexy Extension Cards.

.NET App

You can have your .NET app make the URL API calls with the arguments passed in accordingly so I can say 100% for sure I know this is possible too.


This product has good technical support and the price is not that bad either for what you get so it's worth the read at least, and be sure to check out Talk2M - Industrial cloud for remote connectivity

The eWON Flexy uses an outbound connection across the factory LAN (HTTPS port 443 or UDP 1194). This makes the eWON Flexy to be isolated from Internet by working with private IP address, non reachable from the Internet. No IT/firewall changes are needed to establish communication. A key asset that your IT team will appreciate!

All connections run through industry standard VPN protocols to guarantee a safe and secure connection that prevents network intrusions.


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What you are looking for is a thing like electrical light switch. It has basically all you need and there are many product families to pick from.

If your action is to short circuit this would be enough.

To give an example, look at this.

  • 2
    Thanks. Yes, something similar, but I cannot use these consumer products - it is a factory environment and only an industrial-grade actuator can be considered. The Chinese ones that I linked in question are much closer match than these (because Chinese have LAN and don't require reverse-engineering proprietary protocol to use from my application). The main issue is that I want to find an reputable vendor that makes devices which are easy to provision (configure IP and snail-mail them to remote location - plug and play there). Commented Jun 6, 2017 at 18:04
  • Then you must include the specific industrial standards the solution is required to meet in the question itself. Commented Jun 12, 2017 at 18:50
  • There doesn't seem much choice here, so we can live with anything that is not intended for installation into private homes (or even that if it is intended to be installed on din mount in distributor box) Commented Jun 12, 2017 at 21:15
  • 1
    "anything that is not intended for installation into private homes" is an utterly meaningless requirement. You need to state what industry standards the item must meet. While home and industry use are distinct requirements, there are things out there which are suitable for both uses. Commented Jun 12, 2017 at 23:51

I have not used any of the following relays, but based on your problem description one these may serve you needs:

Online Device Web Controlled Relays

Key Features:

  • Industrial Grade
  • TCP/IP, Web controlled
  • DHCP or Static IP modes
  • RJ45 connector

You might find a switching (rather than dimming) domestic unit along the lines of this LightWave RF Relay. This one is not quite a good fit for your application since it uses 433 MHz OOK (with an ethernet hub if you need), but is not secure. Be aware that a dimmer unit probably won't be suitable (the dimmer circuit wiring relies on the load to sustain the control unit even when switched 'off')

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