ProXR industrial relay controller purchase questions

I’ve been researching which product to buy for lab development work and have settled on the

  • ZADR220PROXR Industrial High-Power Relay Controller 2-Channel + 8-Channel ADC
  • wired Ethernet module

Ultimately I want to run software on a linux host that will send commands to control the relays and possibly accept ADC inputs from the board.

  1. I wanted to get 20 Amp relays in order to be prepared for whatever switching needs my customer throws at me when I arrive on site, but then I read this warning:
    Ideal for high-power switching applications, this relay should never be used for low-power signals.”

Why is this?
I really like the direct push-on connectors on those 20 Amp relays because it eliminates the circuit traces from the switched path; the current flows directly to the relay contacts.

  1. I understand that NCD is not a software house, so how can I get up and running quickly to communicate with this board from a linux computer?

I use Windows 10 regularly for everything, but our production systems run linux.
I know about Base Station to learn the communications and operations of the relay board.
I was hoping to use Node-Red to jumpstart, but it looks like that only supports the wireless sensor line and I read a post from last August that there is no Ethernet library for Python.

I was all set to order a board the other day, but I keep finding more products and more relevant information so my head is spinning with all the choices available. It’s a staggering amount of choices to sift through for a beginner.



  1. So the 20 amp relays can absolutely be used for low power switching. What that should really say is the relay should not be used for signal switching such as data lines. This is because there is a bit of resistance on the relay contacts due to oil coating. You wouldn’t want to switch high bandwidth data signals through the relay but low current loads could be switched through them no problem.

  2. You will need to develop a software application to monitor the A/D inputs and control the relay outputs. This could be developed in C, C++, Python, NodeJS, etc. It is absolutely possible however to do all of this through Node-Red as well, you can use the Function and TCP Client nodes to accomplish this which are available in Node-Red. The full command set for controlling relays can be found here:
    ProXR Quick Start Guide -
    The command set for monitoring the A/D inputs can be found here:
    AD8 8-Channel Analog to Digital Converter Quick Start Guide -
    Documentation for interacting with the board over Ethernet can be found here:
    If you have any questions on this please let us know.

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And to keep the wheel turning I just discovered your Fusion series of boards that is even better for my needs since it accepts 2 communications modules, so I can have wired Ethernet as well as the key fob module, which looks really fun to play with.

Thank you!

Yes, you can install an Ethernet module and Key Fob module in the Fusion board and control from either interface.

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