Visit one of our
other great web sites:

Visit Ozarks AV for the best in AV Equipment

Visit for the best in Agricultural Switching

We Accept:

24-Channel Bluetooth ProXR Relay

Bluetooth Relay Board 24-Channel 3 Amp DPDT + 8-Channel 8/10-Bit A/D


ZADSR243DPDTPROXR_ZBT ProXR Relay Controller
The ZADSR243DPDTPROXR_ZBT features Bluetooth wireless protocol for fast reliable wireless communications to your smart phone or computer. This controller can be expanded to grow with your needs and read analog inputs.!

Bluetooth ProXR Series at a Glance

  • Reliable Sturdy Design
  • 200 to 300 Ft. Wireless Range
  • Pair with Your Computer/Smart Phone/Tablet
  • ProXR Versions
      - Full ProXR Command Set
      - Expandable to 256 Relays
  • 16 Available Timers
  • Mounts as a COM Port for Computer Users
  • Free Android App Available
USB Relay
ProXR with USB Interface

The ZADSR243DPDTPROXR_ZBT is equipped with firmware built into the board that will allow you to control one relay at a time, a bank of relays or all relays at once with manual and automatic refreshing command set.  If you want to control a few relays with your smartphone (and you are savvy at writing such an application), then the ZADSR243DPDTPROXR_ZBT is the ideal choice.

iPhone, iPad, and iPod developers, Apple iOS devices encrypt the Bluetooth protocol deliberately, so our Bluetooth interface is compatible with every computer ever made, including Android, PCs (and every version of Windows that supports Bluetooth), and Linux (and all variants thereof that support Bluetooth), but it will NEVER work with Apple iOS devices… (Yes, we get this question all the time….)

Content on this page requires a newer version of Adobe Flash Player.

Get Adobe Flash player

The ZADSR243DPDTPROXR_ZBT has an onboard USB connection and can plug directly into the USB port of your computer. The board requires 12 volts of power.


Here's Where to Order:

Ratings AC DC
Voltage 240 24
Bluetooth Relay Board 24-Channel 3 Amp DPDT + 8-Channel 8/10-Bit A/D
Part#: ZADSR243DPDTPROXR_ZBT $661.00

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

Bluetooth Configuration

Bluetooth Configuration Module
Easily configure your Bluetooth settings with this USB adapter

Order Today with This Board for Only $29
Stock#: Bluetooth_ZigMo $40/ea

Induction Supression

Induction Capacitors
Add years to the lifespan of the relay by adding an Induction Capacitor to the line when switching inductive loads. 
Induction Suppression $1.99 - $4.89 ea
Available at Checkout

Android App

Bluetooth Android App
Control this relay with your Android Smart Phone or tablet

Download the Free App Today!
Android Bluetooth App FREE

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
Credit Cards Accepted
PayPal Logo

Shipping and Payment Information
Warranty Information
Order Online or Call Us At:
Fax Purchase Orders To

Bluetooth Interface with ProXR Command Set

Inputs for Variable Input Sensor or Contact Closure
ProXR Command Set - Our Most Extensive Command Set we Offer
Reliable Secure Bluetooth Wireless Control for Smart Phone or Computer

About Bluetooth

Bluetooth Wireless is an ideal wireless platform for communicating large amounts of data within a short range.  Bluetooth is great for applications where a computer is not too far away from a device, but you just don't want to bother with connecting wires.  NCD Bluetooth devices need to be paired with a Bluetooth connection on your computer/smart phone/tablet.  This involves opening the Bluetooth control panel on your computer/smart phone/tablet, pressing the "pairing" button on our controller, and finally, using the Bluetooth control panel to add the device to the Bluetooth network.  Once paired, the NCD part number will appear in your Bluetooth control panel, and a new COM port will be available for use on your computer.  The Blue LED on our controller will light as soon as the port is opened.

Smart Phone & Computer Pairing

This Bluetooth Relay will be paired with a Bluetooth connection on your smart phone or computer.  This involves opening the Bluetooth control panel on your computer, pressing the "pairing" button on our controller, and finally, using the Bluetooth control panel to add the device to the Bluetooth network. Once paired, the NCD part number will appear in your Bluetooth control panel, and a new COM port will be available for use on your computer.  To communicate to the device, all you have to do is open the new Bluetooth COM port at 115.2K baud and start sending commands.  The Blue LED on our controller will light as soon as the port is opened.

ZBT Modules

Bluetooth Relay ModuleThis board is equipped with a ZBT Module.  The ZBT communications module adds Bluetooth communications to the board.  The ZBT module is powered from the board.  The board itself will require 12 volts of power and can be hard wired or you can purchase a "wall wart" type Power Supply at checkout.  Bluetooth Module Options

Bluetooth Configuration

Bluetooth ZigMo AdapterConfiguration is easy with the optional Bluetooth ZigMo Modem. Simply connect it to the USB port of your computer with the supplied cable and you will be able to select a COM port, change the baud rate or enter a security pin code.  The Bluetooth ZigMo is available as an option when you purchase your Bluetooth controller.  The ZBT module will pull off the board and can be installed in the ZigMo for configuration.  You can then configure the baud rate and password settings if you require a secure wireless control.  After configuration the ZBT module can be reinstalled in your board and it will be configured to fit your needs.  For more information on Bluetooth configuration see Configuring the Bluetooth Module.

Sending Commands

Base Station Software is available at no charge to get you up and running fast (more on Base Station below).  Once powered up, the controller waits for a ProXR command.  A command consists of a few bytes of data in numerical format (ProXR Enhanced Command Set) 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.  If a command was sent to read the status of the relay the status is sent back.

Android App Available

The app can be downloaded from the Google Play marketplace. Currently it allows you to control up to 8 relays each with individual names. All you have to do is download the app, pair with the desired Bluetooth Board, open the app and select the desired device. Select how many relays your board has, name them if desired. 

Get the app now!

Scan the QR code above with your Android phone to download this free app.

Custom Smartphone App Design

Looking for an app for your Android or iPhone?  Need something that our existing apps can’t do or need a different look?  Contact our app development team to discuss your needs and see how a custom app can be written for your project.  Our developers are familiar with this relay and it’s command set and can build you an app quicker than other developers – this saves you time & money.  Our existing apps can also be modified to fit your needs saving you even more time & money!  Contact us today and see just how affordable an app can be!  Email Travis at:

Induction Suppression

Induction CapacitorPerhaps the most overlooked aspect of relay control is proper handling of inductive loads. Inductive loads can best be defined as anything with a magnetic coil, such as a motor, solenoid, or a transformer.  Controlling a inductive load using this relay controller requires the use of induction suppression capacitors.  The purpose of this capacitor is to absorb the high voltages generated by inductive loads, blocking them from the contacts of the relay.  Without this capacitor, the lifespan of the relay will be greatly reduced.  Induction can be so severe that it electrically interferes with the microprocessor logic of our controllers, causing relay banks to shut themselves down unexpectedly.  In the case of Ethernet devices, customers may experience loss of communications until the device is reconnected.  Capacitors that we offer are available at checkout, for more information view our Induction Suppression Video.

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.

Easy Software Development

Most of our customers write their own program for controlling these devices. Since you can use almost any programming language, you can use one that is most familiar to you so you don't have to learn a new language.  These boards support the Serial Port Profile, meaning they will mount to the computer as a virtual com port. This makes it very easy to send commands to the device.

Plug-In for Visual Studio

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.  Over 40 samples included with this free download!  Component Library.

Base Station Software

Base StationBase Station will assist you in learning how this device functions and is the ultimate reference tool for setting up, testing and controlling this device.  Base Station software supports every feature of this device - no other controller manufacturer even comes close to offering this type of software.  Base Station works by communicating with your controller to identify the model and provides the appropriate graphical user interface for setting up and testing the identified device.  To help you get started and learn this controller Quick Start Guides are available for just about every feature.  As you discover a feature in Base Station a link is provided where you can easily download the Quick Start Guide.

ProXR Relay

We've looked at the interface and the programming now let's take a look at the board design itself.  The ProXR series controllers are manufactured by hand for a highly accurate and reliable design.  Equipped with the XR Expansion Port additional relays can be easily added.  Fully tested before they leave the production facility each ProXR controller is ready to stand up to rigorous demands from heat, cold or vibration.  The best test of all is the numerous boards in the field from customers all over the world in all sorts of conditions.  Take it from us, these controllers will hold up!

Add Relays as Your Needs Grow

The ProXR series controllers are expandable up to 256 total relays.  The controller is fitted with an XR Expansion Port where you can add expansion boards to this relay.  Expansion boards can be added until you reach 256 total relays.  The Expansion Boards get their logic from the main board and will require 12 VDC power. Expansion boards do not need to be the same relay amperage as the main board or other expansion boards.

16 User-Programmable Timers

The ProXR Series controllers have 16 user-programmable timers. Each independent timer can be assigned to any relay, and can be programmed to hold the relay in the On state, or to pulse the relay at the end of the timer.  The ProXR timing features are ideally suited for Watchdog, Keep Alive, and Server Reboot applications, as well as sprinkler systems, gate openers, and lighting applications.  Relay Timing Features support two modes of operation: Duration and Pulse. Duration timing is ideally suited where a device should be activated for a period of time. Pulse timing mode is designed specifically for server reboot applications, whereby, if the timer is not reset periodically by your software, the timer will run out and reboot your computer.

Read Analog Sensors

This ProXR controller offers a 8-Channel 8/10-Bit Analog to Digital Converter in addition to relay control.  Read and control from 8 sensors per board from 0 to 5 volts!

ProXR Enhanced Firmware Installed

This board has ProXR Firmware installed that responds to the full ProXR Command Set.  The ProXR Firmware is the industry leading firmware for controlling relays with more commands and functionality than any other board on the market.  The list of commands and parameters this board is capable of is extensive.  ProXR Enhanced is the newly released enhance version of the ProXR Firmware with more commands, more functionality and better control than ever before!  For a detailed list of all the commands with descriptions see our ProXR Enhanced Command Set.

RoHS Compliant

Compliance to ROHS Standards This board is led free and RoHS Compliant.  If your requirements are for RoHS compliant parts this board is manufactured with RoHS compliant led free parts and solder.

5-Year Warranty/Money Back Guarantee

ProXR Lite series controllers are guaranteed against manufacturing and functionality defects for a full 5 years!  Not to mention a 30-day money back guarantee!  If for any reason you are not happy with a relay purchased from Relay Pros, simply return it within 30 days and we will give you your money back!  Controllers that are damaged by our customers will not of course be warranted under any circumstances. 

Thousands of Relay Cycles

ProXR series controllers are designed for long life, you should expect to get years of service from your controller and literally thousands of cycles from the relays onboard.  With a 5-year warranty and a money back guarantee you have nothing to loose!  Place your order now, while everything is in front of you.


The boards sold are brand new units shipped from our office conveniently located in Missouri.  These boards are completely tested before they are released for shipping  With so many boards on our site it is impossible to stock boards, please allow two to three days production time for your order to ship.  If you have any questions please feel free to call our office at 800-960-4287 or e-mail us at

ProXR Control Is Here!

A more streamlined manufacturing process brings a more durable, reliable and better relay board to the market.  Here's a lists of great features:

    User Friendly Board Design
  • "Wall Wart" or direct power capability
  • Relay status light bar
  • XR Expansion Port
  • Screw terminal or direct relay connections make connecting to the board easy

    ProXR Features
  • Works with the full ProXR Enhanced Command Set
  • 8-Channel 8/10-Bit Analog to Digital Converter
  • Highly reliable relay with industry leading command set
  • 16 programmable timers available

Analog to Digital Conversion

Analog Inputs are very special in that they are sensitive to voltage changes.  Analog to Digital (A/D) conversion is the process of converting a voltage in the range of 0 to 5VDC into a number that can be processed by custom software that you develop.  The ProXR Command Set will allow you to send a command to the board and read voltage levels from 0-5 volts using 8-bit resolution.  8-Bit resolution will read the voltage input (from 0 to 5VDC) and then is interpreted as a value from 0 to 255.  Zero being a contact closure input.

    For Example
  • A voltage input of 0 Volts is interpreted as a value of 0
  • A voltage input of 2.5 Volts is interpreted as a value of 127
  • A voltage input of 5 Volts is interpreted as a value of 255

So if you divide 5 Volts by 255 possible steps (0-255 for 8-Bit resolution), the board is sensitive to voltage changes as small as 0.019 Volts.  This controller has eight A/D inputs, each input is capable of reading a separate voltage from 0 to 5 VDC, provided all voltages can share a common ground.  This is particularly useful for reading temperature sensors (one temperature sensor is built into select boards mostly 4 & 8 channel, shared with analog input number 8).  A/D Inputs are also useful for reading light level sensors, thermocouples, switch closures, or just about any other kind of sensor you can think of.

A/D Sample Programs Available

Eight Different A/D Sample programs are available in the Component Library.  These samples are available as a free download and are compatible with Visual Studio. 


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 Pro & 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 command set in the ProXR Enhanced Command Summary. 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!

Desktop Meters
Desktop Meters can be created for real time level readings of any variable input sensor. "It's like having a meter right on your desk for constant monitoring". Meters can be created for temperature sensors, moisture sensors, light meters and others. Read the sensor and create relay buttons that will allow at-a-glance determination of the relay status. Best of all the increments on the meter can be fully customized to fit your needs and the meters will work with this board!

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 Pro 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 today.


This video will introduce you to the world of Bluetooth Communications and show you how we integrate Bluetooth into our boards.
Also read our Article on Bluetooth Communications.


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 wireless communications and the differences between wireless 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.


Test of the range of our Wireless Communication Options


Test of the range of our IEE 802.15.4 Wireless Communication Options