ProXR RS232 DPDT Relay Controller

Serial Relay Board 32-Channel 5-Amp DPDT with UXP Port


RS232 Relay Controller
Data Collection and Control with Future Expandability in Mind. This ProXR Series Controller is Feature Rich and Ready to Grow with your Needs!
Compliance to ROHS Standards

Control this Device Over the Internet
Signal Switch Compatible

Serial Relay Board 32-Channel 5-Amp DPDT with UXP Port


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The latest version of the ProXR Series have interchangeable communications modules that can be swapped at will. Simply disconnect all power from the board and pull off one module and replace it with another.

RS232 Relay at a Glance

  • Reliable Sturdy Design
  • RS232 Interface w/Choice of RS232 connector
      - Onboard DB9 Connector:
      - Screw Terminal Connector
      - Off the Board DB9 Connector
      - Connects to Any Available COM Port
  • Connects to Third Party Devices
      - Crestron
      - AMX
  • Industry Leading Command Set
      - Send Specific Commands to Trigger Relays
      - Trigger Any or All Relays
      - Program in Almost any Language
      - Read 0 to 5 Volt Sensors
  • Base Station Software
      - Point & Click Interface
      - Use to Connect to Board
      - Read Sensor Levels
      - Read Status of Relays
      - Manually Trigger Relays
  • Expandable up to 256 Relays

This video is a basic introduction to the world of Computer Controlled Switching and Relays in general.
Also read our "Introduction to Computer Control" Article.


Watch to find out the advantages of wired communications and the differences between wired communications.
Also read our Articles on Communication Protocols.


This video will show you what Induction is and how to use Capacitors to Suppress it.
Also read our Article on Induction Suppression.


Learn about the mechanics, applications, and tricks to Analog to Digital Conversion.
Also read our Article on Analog to Digital Conversion.


This movie will show you how to find the Com Port assigned to your Relay Controller.
The first half of the video will show you how to do so in Windows Vista and the second half is using Windows XP.


This movie will explain the different expansion options that can be used with our controllers.


This Product:

Ratings AC DC
Voltage 240 24
Serial Relay Board 32-Channel 5-Amp DPDT with UXP Port
Stock#: ZUXPSR325DPDTPROXR_ZRS $1,062.00

Power Supply Available

PWR12 Power Supply
The PWR12 is regulated power supply providing clean power necessary for the performance of these boards
Power Supplies $24/ea

Desktop Control

Desktop Control & Monitoring
Purchase N-Button fot this controller
N-Button creates desktop widgets to turn relay on/off directly without any programming.

Order Today with This Board for Only $99
Stock#: N-Button $169
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RS232 Relay with
ProXR Command Set and UXP Expansion Port

The Most Powerful Command Set Available Anywhere
Add Contact Closure, Potentiometers & Analog to Digital Conversion Modules
ProXR - The Most Powerful Relay Control Available!

RS-232 ProXR Relay Controller

This ProXR controller is built with the most powerful command set available anywhere.  Simply put, ProXR is a standardized set of commands for controlling relays.  This controller is also equipped with a UXP Expansion Port for adding capabilities beyond basic relay control specifically for the purpose of speaking to various expansion modules. Where the XR Expansion port allows you to add additional relays to the board, the UXP Expansion Port allows you to add functionality to the board. With the UXP Expansion Port you can add Digital Potentiometers, Contact Closure modules and Analog to Digital Expansion Modules to this board.  We offer a complete line of UXP expansion modules to add to this controller to collect data and process data by custom software that you develop. The applications are limitless and the data that you receive such as A/D Sensors or Contact Closures can easily activate relays when specific levels are reached. See more on our UXP Expansion Page.

Once powered up, the relay controller waits for a command.  A command consists of a few bytes of data.  Usually between 2 and 6 bytes.  Once the command has been received, the controller processes the command, and sends you back ASCII character code 85 to signal the completion of your command.  You can send commands to activate relays, deactivate relays, control all the relays at one time, plus you can send commands that tell a relay to turn on for a few seconds, minutes, or hours.  You can assign 16 timers to any of the 256 relays, and set the timers to go off after the duration has expired.  Look at the ProXR Command Set to see the full list of commands available.

The features list of the ProXR series controllers is extensive.  Our ProXR Software helps get you acquainted with the powerful command set.  To download, look for the ProXR Software in the Resources section to the right and bottom of this page.  The ProXR Manual and the mechanical drawing with dimensions and hole layouts can also be found in the Resources section.

Connect this board to the USB port of your computer using a USB to Serial adapter.

Three RS-232 Connection Options

There are three RS-232 connection options available for this controller.

Wire It Up
Plug It In

Choose the connection that fits your needs. The ZRS-A connection is recommended for applications where hard wiring directly to the board is needed. ZRS-B has the fill 9-Pin RS-232 connector on the board. The ZRS-AB Has the fill 9-Pin connector but is is located off the board for applications where the board may be place inside an enclosure an the RS-232 connector needs to reach to the side of the enclosure.  You can choose one of these connection options at checkout.

Built with Expandability in Mind

Out of the box, the ProXR series controllers are ready to control 256 relays.  You may not have 256 relays just yet, but if your application grows, then the controller is ready to grow with you.  The ProXR series controllers are built from the ground up to be expanded.  When you need more relays, the XR Expansion port will allow you to add another bank of relays (any kind you need), with programming changes taking minutes instead of hours.  No complicated protocols, just simplicity, built into the controller from the very beginning.

Using XR and UXP Together

This controller is equipped with both XR and UXP ports and you can use both ports simultaneously. This allows you to add and control more relays through the XR port plus add A/D, Contact Closures or Potentiometers to this board through the UXP port. This can all be controlled through the same virtual COM port on your computer. These Expansion Boards can be purchase with the controller or purchased at a later time when you have a need to expand.

DPDT RelayDPDT Relay Controller

This device has DPDT relays installed.  A single DPDT relay is made up of 2 SPDT switches.  Each relay acts as two switches that are activated at the same time.  This allows two independent signals to be switched at one time.  In effect, there are two independent switches on a single DPDT relay - they will always switch together.

Time Schedule Graphic
There are two connectors with Normally Open, Normally Closed and Common for each relay allowing two separate connections.  The picture above shows the 4-channel connectors.  The diagram to the right shows the how the arms of the common connector swing from the Normally Closed to the Normally Open positions when energized.  Wiring to either the NO or NC can produce your desired results.  For more information on selecting the correct relay amperage for your application see Choosing a Proper Amperage.

About Universal Expansion Ports

If you need to add capabilities beyond basic relay control to your application, then you may want to consider using one of our controllers equipped with a UXP Expansion Port. UXP is a standardized data port, specifically for the purpose of speaking to various expansion modules. This Relay Controller is equipped with a UXP port, allowing you to take advantage of extended commands to speak to our growing line of I/O expansion modules.

Read More About Universal Expansion Ports

NCD Component Library

Fully functioning programs for the ProXR Series Controllers are included with the NCD Component Library. With the NCD Component Library we've "started" the programming for you. We say started because these are fully functioning samples but we've also included the source code so you can customize them to your exact needs.  The NCD Component Library is a plug-in for the Visual Studio 2005/2008 that greatly simplifies the communications to the NCD product line.  The samples can be run in Visual Studio and fully customizable to your needs.  Many different ProXR Series samples are available including Relay Control, Read Status, Analog to Digital Conversion, Motion Detection, and Timing Features to view screen shots of each sample visit our NCD Component Library Page..  Start by downloading the FREE NCD Component Library and you will be communicating with any NCD device faster that ever! 
ProXR Relay Sample 1
This sample demonstrates control and status read of up to 8 Relays.
Compatible with all ProXR Series Relay Controllers.
The above screen shot shows one of the four available fully functioning ProXR Series samples that are available with the NCD Component Library.  View all the examples on our NCD Component Library Page.


N-Button & N-Button Lite is software that allows you to configure buttons to control relays and read the status of those relays without programming. You can also create meters for reading variable input sensors connected to the board in real time!  N-Button will allow you to create unlimited widgets and N-Button Lite will allow you to create up to 8 widgets.

Custom Buttons
When you create custom buttons in N-Button & N-Button Lite you can use any of the commands that are in a ProXR Command Set that is available with this relay. You can find the full command set here. It's quite extensive and you can configure the buttons to activated these commands. These buttons will be on your desktop of your computer and when you click on a button it will send the command to the board provided the board is connected to the computer. You can also change the shape, color and text of each button so you will know exactly what each button controls.
Relay Buttons
Relay Button widgets turn on/off relays directly. It has never been easier to control relays, no programming skills required. Create a button that turns a relay on and another one to turn the relay off or create a button that toggles the relay on and off. It's up to you and easy to configure with the N-Button Lite software!

Relay Status Relay Status widgets shows the status of the relay automatically. Just a glance at your desktop will show the status of the relay!

Save 40% on N-Button Today
Limited time offer! Order the N-Button Lite with a relay board and get it for the unbelievable price of just $29.00. That's a discount of 40% off the retail price! If you purchase the full N-Button it's just $99.00 with the purchase of a relay board and that's a 41% savings off retail price! Desktop control, sensor meters and backgrounds plus all the customization for just one low price, purchase your copy of N-Button Lite today.


Serial Relay Board

The ZUXPSR325DPDTProXR_ZRS Serial Relay Board is equipped with firmware built into the board that will allow you to send commands to the board to energize the relay.  The RS232 interface will allow you to connect the board to the DB9 port on your computer.  The board will mount to any existing COM port.

ZUXPSR325DPDTProXR_ZRS The Ideal Choice

The ZUXPSR325DPDTProXR_ZRS Serial Relay Board allows you to program in almost any language and has the ProXR Command Set, the industry leading command set for sending commands to control relays and read the inputs on the board. 

Connect to Other Devices

The ZUXPSR325DPDTProXR_ZRS_ZRS Serial Relay Board Connects to any devices through a DB9 or Direct Wire Connection that has the ability to send numerical commands.  Add relay control to Crestron, AMX or any system that has a DB9 interface.