The ProXR Lite SPDT Relay Board

ProXR Lite Relay

In this tab we'll take a look at the board design itself.  The ProXR Lite series controllers are machine manufactured for a highly accurate and reliable design.  Fully tested before they leave the production facility each ProXR Lite 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!

No Break-A-Way Tabs

This board DOES NOT have Break-A-Way tabs.  When the blank board stock was manufactured the scoring for the tabs was not done.  All other functions of this ProXR Lite board remain the same.  It just can't be made smaller.  NCD made a few of these before noticing the scoring was not done.  They offered these boards to us at a discounted price of $40 off, if you don't need a smaller footprint this board is a great option.

Not Expandable

Unlike it's big brother, the ProXR Series, the ProXR Lite series controllers are NOT expandable.  The firmware still thinks 256 relays are available but the relay portion of the controller only responds to the first 1, 2, 4 or 8 relays in Bank 1.

ProXR Command Set

The ProXR Firmware installed on the board has more commands and functionality than any other board on the market!  The list of commands and parameters this board is capable of is extensive!  Writing your own program can be done in just about any programming language so you can use what you are comfortable with!  Software is available for those who aren't programmers.  You can find the complete command set in the ProXR Quick Start Guide.

Base Station Software

Base Station Software was designed to help you learn the ProXR command set.  Explore ProXR features using it's Graphical User Interface.  Watch data bytes flow to and from the board, so you easily understand the command execution process.  There is no faster or easier way to learn how to automate than Base Station, as it was designed to work with the complete array of communication modules.  Base Station software supports every feature of this device - no other controller manufacturer even comes close to offering this type of software. 

Easy Software Development

Most of our customers write their own program for controlling these relays.  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 board.  Not a programmer, check out N-Button!  Software that allows you to configure buttons to control relays and read the status of those relays without programming using point-and-click action.  Click Here for More

Essential Power Requirements

Applying Good clean power to the board is essential for the operation of the board.  Not only for the switching of the relays but the firmware that processes the commands.  Without good steady clean power from a regulated power supply the board simply will not function correctly.  All boards on the site require 12 VDC power.  The PWR12 US power supply is a 120VAC to 12VDC 1.25A 60Hz regulated power supply and it plugs into the barrel connector on the board.  The output connector is a 2.1mm I.D. x 5.5mm O.D. x 9.5mm Female R/A barrel connector.  We also carry an international power supply with interchangeable adapters for international customers. Learn More

Read Analog Sensors

All ProXR Lite controllers offer 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 (0 being a dry contact)!  A/D inputs are ideal for reading the on/off status of switches, connect a switch between input and ground and software may then be used to monitor the contact closure status of the switch.  AD inputs can also be used for reading variable resistance signals, the board will then will return a value between 0-255.  Click the grey Data Sheets tab above and look for the AD8 Quick Start Guide to see the full AD command set.

SPDT Relay Installed

This device has SPDT relays installed.  SPDT Single Pole Double Throw Relays have three connections - Common, Normally Open, and Normally Closed.  When the relay is off, the common is connected to the normally closed connection of the relay.  When the relay coil is energized, the Common swings to the Normally Open Connection of the Relay.  You can wire the device you are switching to either the Normally Open or the Normally Closed position using screw terminal connections.  The maximum guage wire the terminal can handle is 14 ga but we have used up to 12 ga solid core for several applications with no issues.

2-Million Cycles

ProXR series controllers are designed for long life, you should expect to get years of service from your controller and literally 2-million cycles from the relays on board.  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.

This Board is RoHS Compliant

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.

30-Day Warranty/Money Back Guarantee

ProXR Lite series controllers are guaranteed against manufacturing and functionality defects for a full 30 days!  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. 

Induction Suppression

Perhaps 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 board requires an induction suppression capacitor for each relay being used.  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 interferes with the logic of the board, causing relay banks to shut down unexpectedly.  For more information view our Induction Suppression Video.

Shipping

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 sales@relaypros.com.

ProXR Lite 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
• Single Pole Double Throw Relays Installed
    - Wire to Normally Open or Normally Closed Position
• Screw Terminal Contact Closure/Relay Connections
• RoHS Compliant

ProXR Lite Features
• Industry Leading ProXR Command Set
• 8-Channel 8/10-Bit Analog to Digital Converter
• Highly Reliable Board
• Assign up to 16 Programmable Timers

ProXR Lite Limitations
• This controller cannot be expanded

USB Relay Control

Mounts as a Virtual COM Port

The USB Relay connects directly to your computer's USB port and appears as a standard COM port. On Windows machines with internet access, the correct FTDI drivers install automatically.

Once powered, the board listens for compact serial commands - typically 2 - 6 bytes. After processing your command, it returns ASCII code 85 to confirm successful completion.

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USB Communications Module

The USB Relay module makes controlling relays simple. Plug it into any available USB port and begin sending standard serial commands to switch relays or read A/D inputs.

Every NCD USB interface uses a genuine FTDI FT232-RL USB-to-Serial converter chip for maximum stability and cross-platform support. With drivers available for Windows, macOS, Linux, and more, the module communicates using a Virtual COM Port for easy software integration.

Once installed, open the COM port at 115.2K baud and start exchanging data immediately. On-board USB, TX, and RX LEDs provide live communication feedback. The module uses a durable USB Mini connector - our preferred interface for longevity and reliability.

Simply download the latest Base Station Software, install it on your Windows PC, and your COM port will appear automatically, ready for communication.

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Virtual COM Port

A Virtual COM Port (VCP) registers as a standard serial port on your computer, allowing you to use new or existing serial-based software with any NCD Industrial controller.

Because VCP communication is one of the easiest and most universally supported communication formats across operating systems, languages, and hardware platforms, the ZUSB USB Interface is the ideal tool for learning, testing, and operating NCD devices.

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Induction Considerations

For most applications, the onboard capacitors provide more than enough suppression, and users will never encounter communication issues.

However, switching inductive loads such as motors can create higher levels of electrical noise, and in those situations additional precautions may be necessary. Testing is recommended for motor-based installations to ensure reliable communication.

If communication problems do occur in these high-induction environments:

• An RS-232 communications module provides a more noise-resistant interface.
• When USB connectivity is still needed, a USB-to-RS-232 adapter paired with the RS-232 module offers the stability of RS-232 with the convenience of USB.
• RS-232 naturally blocks induction to safer levels, allowing the adapter to operate without errors even in demanding motor-control setups.

For all other users and non-motor applications, standard USB operation typically performs without complications.

The ProXR Lite SPDT Relay Board

Built for Reliability. Engineered for Simplicity

ProXR Lite Relay Design

The ProXR Lite series is machine-manufactured for consistent, high-precision performance. Every controller is fully tested before it leaves the production floor, ensuring dependable operation in tough environments - heat, cold, vibration, and everything in between. With thousands of units in the field worldwide, these boards have proven they can take a beating and keep on switching.

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ProXR Command Set

ProXR Firmware is one of the most feature-rich relay command sets available.
You get access to a huge library of functions, timers, parameters, and control options - all programmable in nearly any language. Prefer no-code? Software is available, too.
Find the full command set in the ProXR Quick Start Guide.

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Easy Software Development

Most customers write their own control programs, and the ProXR Lite makes that easy.
Because the board uses the Serial Port Profile, it mounts as a virtual COM port, allowing simple command-based control from nearly any programming language.
Not a programmer? N-Button Lite offers point-and-click relay control and status monitoring - no code required. Click Here for More

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Read Analog Sensors

Every ProXR Lite board includes an 8-Channel 8/10-Bit A/D Converter.
Monitor up to eight sensors from 0 - 5VDC (0V can be read from a simple contact closure). Use A/D inputs for:

• Switch status monitoring
• Variable resistance sensors
• Simple automation logic

Values return as 0 - 255.
See the AD8 Quick Start Guide for full A/D command documentation.

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Relay Activator and Analog Inputs

The Relay Activator control panel lets you use analog inputs to directly control onboard relays. Just connect buttons or switches to the analog inputs and trigger simple on/off actions for manual relay control. Each of the eight inputs can be assigned one of eight functions, including turning relays on or off, toggling relay states, flashing a relay momentarily, toggling the flash function, turning all relays on, turning all relays off, or generating push-notification events using N-Button Software. Click the gray Relay Logic tab and check out Example 6 to see how to wire a manual switch into your setup. Download the Relay Activator Quick Start Guide here: Relay Activator Quick Start Guide.

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SPDT Relay Installed

SPDT (Single Pole Double Throw) relays include three terminals: Common (COM), Normally Open (NO), and Normally Closed (NC)

• When the relay is off, COM is connected to NC.
• When the relay is energized, COM switches to NO.

Your load can be wired to either the NO or NC terminal depending on whether you want the device to turn on when the relay activates or when it releases. Examples of wiring methods can be found in the gray Relay Logic tab.

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2 Million+ Cycles

ProXR relays are built for longevity - expect years of reliable operation and millions of mechanical cycles. Every board ships with a 5-year warranty and 30-day money-back guarantee.

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Not Expandable (By Design)

ProXR Lite keeps things simple.
Unlike the full ProXR Series, Lite boards do not support relay expansion. While the firmware still reports up to 256 potential relays, only the first 1, 2, 4, or 8 relays in Bank 1 are active depending on the model you choose.

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Break-A-Way Tabs for a Smaller Design

Need a smaller footprint? The ProXR Lite PCB includes Break-A-Way Tabs, allowing the board to fit into optional undrilled enclosures or tight-space installations.

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RoHS Compliant & Lead-Free

All ProXR Lite controllers are built with RoHS-compliant components and lead-free solder.

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5-Yeary Warranty & Guarantee

Every ProXR Lite controller is covered by:

• 5-Year Functional Warranty
• 30-Day Money-Back Guarantee

If you're not satisfied, send it back for a refund within 30 days. (Damage caused after delivery isn't covered.)

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Essential Power Requirements

Clean, regulated power is critical.
A stable 12VDC supply ensures both the relay coils and onboard firmware operate correctly. Unstable or noisy power can cause improper switching or communication issues.
We recommend the PWR12-US (120VAC → 12VDC @ 1.25A) or our international supply with interchangeable adapters.
Learn More

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Shipping

All boards ship directly from our Missouri facility. Each unit is built and tested at the time of order - please allow 2 - 3 days for production. We ship primarily through UPS, but we're happy to use FedEx or DHL for international orders when you provide your account number. Questions? Call us at 800-960-4287 or email sales@relaypros.com.

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Induction Suppression

Inductive loads - motors, solenoids, transformers - generate high-voltage spikes.
Each relay controlling an inductive load must use an induction-suppression capacitor. Without it:

• Relay life is significantly reduced
• High-voltage feedback can disrupt logic and shut down relay banks

See our Induction Suppression Video Video for guidance.

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Base Station Software

Base Station is the fastest way to learn and control the ProXR Lite board. Explore every feature through an intuitive GUI while watching live data flow to and from the board.
Designed to work seamlessly with the entire family of communication modules, Base Station supports every feature the board offers - far beyond what other manufacturers provide. More on Base Station can be found in the Base Station tab.

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ProXR Lite at a Glance

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
• Single Pole Double Throw Relays Installed
    - Wire to Normally Open or Normally Closed Position
• Break-A-Way Tabs Lets you Decide the Board's Size
• Screw Terminal Contact Closure/Relay Connections
• RoHS Compliant

ProXR Lite Features
• Industry Leading ProXR Command Set
• 8-Channel 8/10-Bit Analog to Digital Converter
• Highly Reliable Board
• Assign up to 16 Programmable Timers

ProXR Lite Limitations
• Not expandable (fixed relay count)

The ProXR Command Set

ProXR Firmware

The firmware on the Ethernet Relay board supports the ProXR Command Set, offering more commands and functionality than any other relay board on the market! The list of available commands and parameters is extensive, giving you full control. You can write your own control program in almost any programming language.

Key Features

• Extensive Command Set: More commands and functionality than any other relay board.
• Programming Flexibility: Compatible with nearly any programming language.
• User-Friendly Software: Free software available for non-programmers to easily control relays without coding.

Introduction

The ProXR Series Controllers allow you to control up to 2048 relays depending on your controller model.  Relays are divided into groups of 8 called banks, and are addressed by their bank number.  For instance, a ProXR series controller with 32 on-board relays has four on-board banks, the on-board relays respond to bank values of 1-4.  If you use the XR Expansion port to add another bank of 24 relays, then you will need to specify bank values of 5-7 to control the extra relays.  The firmware doesn’t actually know how many relays are attached to the relay controller, it is up to the user to define how many relays are attached to the controller using Base Station Software.  The ProXR CPU will assume you have connected the maximum number of supported relays to your controller.  In the ProXR Quick Start Guide, you will see two commands that appear to do the same thing, for example:

  254 0-7 Turn Off Individual Relays
  254 100-107 Bank# Turn Off Individual Relays in Bank
  254 8-15 Turn On Individual Relays
  254 108-115 Turn On Individual Relays in Bank
  254 16-23 Get the Status of an Individual Relay
  254 116-123 Bank# Get the Status of an Individual Relay in Bank
While the outcome is the same, these commands function in slightly different ways.

For instance:
  254 8 Turn On Relay 1
To make this command work, you will send a 254, then a 8 to activate a relay. By default, relay bank 1 will be affected by this command. However, you can redirect this command to a different relay bank using the following command:
  254 49 2  Direct Commands to Relay Bank 2
Then you can send:
  254 8 Turn On Relay 1 in Bank 2

Here are a few more Bank Specified Examples:
  254 49 1 Direct Commands to Relay Bank 1
  254 8 Turn On Relay 1 in Bank 1
  254 49 2 Direct Commands to Relay Bank 2
  254 8 Turn On Relay 1 in Bank 2
  254 9 Turn On Relay 2 in Bank 2
  254 10 Turn On Relay 3 in Bank 2
  254 49 3 Direct Commands to Relay Bank 3
  254 8 Turn On Relay 1 in Bank 3
  254 11 Turn On Relay 4 in Bank 3
  254 12 Turn On Relay 5 in Bank 3
  254 13 Turn On Relay 6 in Bank 3
  254 14 Turn On Relay 7 in Bank 3
  254 49 0 Direct Commands to All Relay Banks
  254 8 Turn On Relay 1 in All Relay Banks

This command structure has the advantage of being very fast and efficient. However, if power to the controller is ever lost, commands will automatically be directed to bank 1 when power to the controller has been restored. This command methodology is generally advisable for ProXR controllers with 8 or fewer relays. When working with more than 8 relays, we generally advise users to use Bank Directed commands as shown in the following examples.

Turns Off Relays in the Currently Selected Relay Bank

This command will control the Off status of specified relays in the Currently Selected Relay Bank.  This command has optional parameters <1-7> for controlling the Off status of the remaining relays, 1 being the next relay in sequence, 2-7 being all possible subsequent relays in the selected relay bank.  A value of 0 refers to the first relay in the specified relay bank, 7 being the 8th and final relay of the selected Relay Bank. This command sends byte value 85 back to the user when the operation has been completed.

Send Bytes:	Byte 1:	Byte 2:	Byte 3:
Function:	Command	Command	Optional Parameters
Decimal Values:	254	0-7	1-7
Hex Values	0xFE	0x00 - 0x07	0x01 - 0x07
Receive Byte:	Decimal:	85
	Hex:	0x55

Turns On Relays in the Currently Selected Relay Bank

This command will control the On status of specified relays in the Currently Selected Relay Bank.  This command has optional parameters <1-7> for controlling the On status of the remaining relays, 1 being the next relay in sequence, 2-7 being all possible subsequent relays in the selected relay bank.  A value of 0 refers to the first relay in the specified relay bank, 7 being the 8th and final relay of the selected Relay Bank.  This command sends byte value 85 back to the user when the operation has been completed.

Send Bytes:	Byte 1:	Byte 2:	Byte 3:
Function:	Command	Command	Optional Parameters
Decimal Values:	254	8-15	1-7
Hex Values	0xFE	0x08 - 0x0F	0x01 - 0x07
Receive Byte:	Decimal:	85
	Hex:	0x55

Read the Status of Relays in the Currently Selected Relay Bank

This command will report the On/Off status of Relays 0-7 in the Currently Selected Relay Bank.  This command sends byte value of 0 of 1 back to the user when the operation has been completed, 0 reporting an Off status and 1 reporting an On status.

Send Bytes:	Byte 1:	Byte 2:
Function:	Command	Command
Decimal Values:	254	16-23
Hex Values	0xFE	0x10 - 0x17
Receive Byte:	Decimal:	0 or 1
	Hex:	0x00 or 0x01

Full Command Set

These are only a few examples from the ProXR Command set so you can get an idea of the command structure.  Download the ProXR Quick Start Guide to view the full command set ProXR Quick Start Guide.

Base Station Software

Base Station Software was designed to help you learn the ProXR command set!  No other relay board manufacturer even comes close to offering this type of software!  Explore ProXR features using it's Graphical User Interface.  Watch data bytes flow to and from the board, so you easily understand the command execution process.  There is no faster or easier way to learn how to automate than Base Station, as it was designed to work with all the communication modules we offer!  You only need a Windows 8 or 10 Computer to Run Base Station. 

Base Station Features

There are some useful features to look for when using Base Station Software to control, test, or configure your device:

• At the bottom left corner of each window there is a link to relevant documentation for your device
• In the Control Command Set Window, and many others, there is a MORE or LESS option at the top right corner.  Selecting MORE allows you to view specific communication details.
• All the functions of the command set are available as a point-and-click interface plus you can see the command that is being sent to the board!

The AD8 Command Set

Reading Switches/Variable Resistance Signals

This controller includes eight channels of 8/10-bit Analog-to-Digital Converters capable of reading 0 - 5V DC signals. The ADCs allow you to monitor external sensors or detect contact-closure inputs. Connect temperature sensors, light sensors, current sensors, buttons, switches, or any device that outputs a 0 - 5V signal or simple contact closure.

• With 8-bit resolution, inputs convert 0 - 5V into values from 0 to 255
• With 10-bit resolution, values range from 0 to 1023

Resolution is software-selectable. Request an analog value from the controller and it responds instantly.

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Analog Inputs Controlling Relays

ProXR AD8 controllers allow analog inputs to directly control onboard relays. Inputs can be assigned to turn relays on or off, toggle states, flash relays, enable/disable flashing, send push-notification data, and more.

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Analog to Digital Connections

AD8 controllers are designed for stable sensor and switch monitoring. A/D inputs should never be left floating - each input must connect to a voltage or ground.

A built-in 10K pull-up/pull-down resistor (jumper-selectable) ties each input to +5V or ground to prevent floating conditions. While this resistor adds slight loading, the improved stability far outweighs any minor interference.

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AD8 Command Set

The AD8 Command Set reads analog voltages using the controller's 8-channel 8/10-bit ADC.

• 8-bit mode: Converts 0 - 5V to values from 0 to 255
• 10-bit mode: Converts 0 - 5V to values from 0 to 1023

Because 10-bit values transmit as two bytes (MSB and LSB), reconstruct the full reading using: 10BitValue = (MSB - 256) + LSB

Reads the 8-Bit Analog Input of Channels

This command will read the Analog Input of Channels 1-8 and return an 8-bit value for each.

Send Bytes:	Byte 1:	Byte 2:
Function:	Command	Parameter (Channel 1-8)
Decimal Values:	254	150-157
Hex Values	0xFE	0x96 - 0x9D
Receive Byte:	Decimal:	0-255
	Hex:	0x00-0xFF

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Full Command Set

These are just a few examples from the AD8 Command Set to help illustrate the command structure. For the complete list of commands, download the AD Quick Start Guide.

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Base Station

Base Station software lets you read all analog inputs in real time and also displays the exact commands being sent. This makes it easy to integrate those commands directly into your own applications or custom programming.

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Relay Activator

Relay Activator and Analog Inputs

The Relay Activator control panel lets you use analog inputs to directly control onboard relays. Just connect buttons or switches to the analog inputs and trigger simple on/off actions for manual relay control. Each of the eight inputs can be assigned one of eight functions, including turning relays on or off, toggling relay states, flashing a relay momentarily, toggling the flash function, turning all relays on, turning all relays off, or generating push-notification events using N-Button Software.

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Relay Activator for Manual Control

Relay Activator is ideal for applications that rely on computer control but still require occasional manual operation. By connecting buttons or switches, you can take direct manual control of any relay. For example, you can turn a relay on via computer and turn it off later using a physical switch - true seamless control from both directions. Download the Relay Activator Quick Start Guide here: AD8 Relay Activator Quick Start Guide.

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N-Button Software

Create Desktop Meters

Using N-Button software, you can create desktop meters that display real-time sensor readings from the AD8 inputs - like having a live meter right on your desktop for constant monitoring. Meters can be built for temperature, moisture, light, and many other sensors with output ranges between 0 and 5 volts. With eight available inputs, you can create and label a custom meter for each one - our example here is labeled "Soil Moisture". Best of all, meter increments are fully customizable to match your application. N-Button Lite and N-Button Pro are available for purchase at checkout.
Visit our N-Button Page

N-Button Lite - Relay Control Without Programming

Relay Software

N-Button Lite is third-party software (sold separately) that gives you full relay control without writing a single line of code. It may look simple at first glance, but don't let that fool you - this is a surprisingly powerful tool with a wide range of real-world applications.

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Create Buttons & Widgets

N-Button Lite/Pro lets you build floating desktop widgets that can:

• Control relays and other external devices
• Send custom data
• Launch applications
• Trigger HTTP requests
• Send data lists

It supports Serial/USB and Network connections, and you can even access your widgets remotely. Most actions are point-and-click - no programming required.
N-Button also includes special widgets designed specifically for the boards on this site.

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Supports Up To 16 Widgets

N-Button Lite offers the same widget types as the Pro version but is limited to 16 total widgets - perfect for smaller setups or budget-friendly applications.
Need more? You can upgrade to N-Button Pro at any time.

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USB and Network Compatible

N-Button Lite works over Serial/USB or Network connections between your computer and the relay board. Add or modify widgets easily using N-Button Lite Manager to create the exact look and behavior you want. N-Button Lite supports this relay board and andy ProXR Relay board with up to 16-widgets.

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Create 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 (one click turn relay on another turns it off).  It's up to you and easy to configure with a point-and-click interface!

Create Custom Buttons

When you create custom buttons in N-Button Lite you can use any of the commands that are in a ProXR Command Set (provided you purchase a ProXR relay) the industry leading command set and it's quite extensive!  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.  The color can even change with the status of the relay (on or off)!

Create Relay Status Widgets

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

Create 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.  Choose an Analog to Digital controller (look for AD in the part number) purchase a copy of N-Button Pro or N-Button Lite and you can read the A/D levels right on your desktop!   If you have an application where you need to track sensor levels you will have a live real time meter right on your desktop!

Backgrounds

Add some style to your desktop with N-Button Pro and N-Button Lite you can create backgrounds and holders for your buttons like the virtual Key Fob.  Create your own button functions or use one of our pre-installed "V" Fobs ready for download.

Control More Than Just Relay Boards

Customized Button widgets can be set to send specified data to any other connected devices besides relay boards. It can be set to open a file, a folder or a program, run any application or send http request. It also supports send data list.  A group of data can be sent to serial port or IP address just by clicking the created button.

Power & More

SPDT Relay Controller Specifications

This table outlines key performance ratings for all NCD SPDT Relay Controllers, based on 12VDC operation at 70°F (21°C). Many values are estimated and may be updated over time. Some ratings reflect standard, out-of-the-box settings without performance optimizations applied.

Processing times can vary depending on background services and the commands you use. Standby power values assume no communication module is installed and no relays are active. For a more accurate power estimate, be sure to include the consumption of any installed communications module and any energized relays.

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SPDT Relay Installed

SPDT (Single Pole Double Throw) relays include three terminals: Common (COM), Normally Open (NO), and Normally Closed (NC)

• When the relay is off, COM is connected to NC.
• When the relay is energized, COM switches to NO.

Your load can be wired to either the NO or NC terminal depending on whether you want the device to turn on when the relay activates or when it releases. Examples of wiring methods can be found in the gray Relay Logic tab.

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2 Million+ Cycles

ProXR relays are built for longevity - expect years of reliable operation and millions of mechanical cycles. Every board ships with a 5-year warranty and 30-day money-back guarantee.

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SPDT Relay Specs

Specs of NCD SPDT Relay Boards	Minimum	Nominal	Maximum	Notes
Operational Voltages	10VDC	12VDC	15VDC
Standby Power Consumption	35mA	100mA	200mA	No Active Relays, No Com Module
Relay Power Consumption	28mA	35mA	60mA	Consumption of Each Activated Relay
Operational Temperature Range	-40°F (-40°C)	70°F (21°C)	185°F (85°C)	Theoretical Component Limits Shown
Storage Temperature Range	-67°F (-55°C)	70°F (21°C)	185°F (85°C)	Theoretical Component Limits Shown
Operational Ambient Air Humidity	0%	50%	70%	Non-Condensing Humidity Values Shown
Relay Activation Time	4ms	5ms	10ms	Needs Further Validation
Relay Deactivation Time	5mS	10mS	15mS	Needs Further Validation

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Communication Modules

Communication Module Specifications

This table provides a quick, clear overview of all NCD Communication Modules. While each module operates at 3.3VDC, the values shown here reflect the impact on a 12VDC master controller at 70°F (21°C). Use the maximum ratings for power-budget planning - they represent short-term peak consumption and may include estimated values that are updated as modules evolve.

Communication Module Power Consumption

Specs of NCD Communication Modules	Minimum	Nominal	Maximum	Notes
Operational Temperature Range	-40°F (-40°C)	70°F (21°C)	185°F (85°C)	Theoretical Component Limits Shown
Storage Temperature Range	-67°F (-55°C)	70°F (21°C)	185°F (85°C)	Theoretical Component Limits Shown
Operational Ambient Air Humidity	0%	50%	70%	Non-Condensing Humidity Values Shown
USB Module Power Consumption	N/A	N/A	N/A	USB Modules are Powered by the USB Port Do Not Consume Device Current
RS-232 Module Power Consumption		10mA	20mA
Ethernet Module Power Consumption	58mA	82mA	100mA
WiFi Bluetooth USB Module Power Consumption	37mA	50mA	100mA	Up to 300 Foot Indoor Wireless Range, Unobstructed. Up to 50 Foot Range Through Walls
900MHz Wireless Module Power Consumption	13mA	30mA	50mA	Up to 1,000 Foot Indoor Wireless Range, up to 2 Mile Outdoor Wireless Range using Included Antennas. Up to 28 Miles Outdoor Wireless Range using High-Gain Antennas.
KFX Wireless Key Fob	11mA	15mA	25mA	Up to 200 Feet Outdoor Wireless Range using 1, 2, 3, 4, or 5 Button Key Fobs. Up to 700 Feet Outdoor Wireless Range using 8-Button Remotes

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A/D Inputs

AD8 Analog Input Usage Notice

Analog inputs should never have voltage applied when the controller is powered down. If your application requires voltage to remain on an input, add a 220-ohm current-limiting resistor to each channel to protect the controller from damage.
Keep all analog inputs within the 0 - 5VDC range - exceeding this limit can permanently damage the on-board CPU. Most inputs include a 10K pull-up or pull-down resistor to keep the line stable when unused, but note that this resistor may introduce a slight bias in readings for certain sensors.

Accessories

Relay Logic

Relay Wiring Samples

This page provides simple examples showing how to wire a single relay - or multiple relays - for common switching applications. We use a light as the example load, but you can substitute a gate controller, security panel input, dry contact device, motor trigger, or most other switched loads. These wiring samples demonstrate different ways to connect relays to achieve the switching behavior you need.

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Relay Types

SPDT Relay

SPDT (Single Pole Double Throw) relays include three terminals: Common (COM), Normally Open (NO), and Normally Closed (NC).

• When the relay is off, COM is connected to NC.
• When the relay is energized, COM switches to NO.

Your load can be wired to either the NO or NC terminal depending on whether you want the device to turn on when the relay activates or when it releases. Examples below demonstrate both wiring methods. The SPDT relays offered on this site are 5-Amp, 10-Amp and 20-Amp models.

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SPST Relay

SPST (Single Pole Single Throw) relays provide two terminals: Common (COM) and Normally Open (NO).

When the relay coil is energized, COM connects to NO to power the load. The only SPST relays offered on this site are our 30-Amp models. All SPST examples shown on this page apply to these relays as long as the example does not require a Normally Closed terminal.

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DPDT Relay

A DPDT (Double Pole Double Throw) relay contains two SPDT switches that operate together.

• Each side includes its own COM, NO, and NC terminals.
• Both internal switches change state at the same time.

This allows you to control two independent circuits with one relay. Wiring for each side of a DPDT relay follows the same rules as an SPDT relay, so the examples on this page apply directly. We offer the DPDT relays in 1-Amp, 3-Amp and 5-Amp models on ProXR boards starting at 8 relays.

Relay Grouping in the ProXR Command Set lets you combine individual relays to function like a DPDT relay using separate channels. This is ideal when you need to control multiple relays simultaneously or exceed the 5-Amp switching limit of our standard DPDT relays.

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Relay Logic Examples

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Example 1 - Simple Off/On Control

This example shows the most basic way to use a relay to switch a device such as a light. When the relay energizes, its NO (Normally Open) contact closes to COM (Common), completing the circuit and turning the light on.

Only a single power wire is switched in this setup, making it the simplest method for controlling a light - or any device - using a relay.

Use this example for switching a light or any device you want to power only when the relay is on.

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Example 2 - Simple On/Off (Using NC Contact)

This wiring method keeps the device on by default. The relay switches a single power wire through the COM (Common) and NC (Normally Closed) terminals.
When the relay is not energized, the NC contact is closed to COM and the light remains on.
When the relay energizes, the NC contact opens, interrupting power and turning the light off.

This approach is ideal for devices that stay on most of the time, reducing relay wear since it doesn't need to remain energized to keep the device powered. It's also a useful method for power-cycling equipment - energizing the relay momentarily will turn the device off.

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Example 3 - AND Logic Using Two Relays

This example shows how two relays can work together so a light turns on only when both relays are energized. This creates an AND Logic condition:
Relay 1 AND Relay 2 must be on for the light to receive power.

A single power wire is switched, but it must pass through both relay contacts before reaching the light. This setup is ideal when two conditions must be met at the same time - such as requiring input from multiple sensors or system parameters.

MirC/MirX Users: This wiring requires two contact closure inputs on the sender board before the receiver's relay activates. Use this approach when two independent outputs must close before turning on the light.

For example, a light could turn on only when:
• A light sensor detects it's dark AND
• A motion sensor detects activity in the room

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Example 4 - AND Logic Using Three Relays

This example expands on the previous AND Logic concept. Here, the light will turn on only when all three relays are energized:

Relay 1 AND Relay 2 AND Relay 3 must be on for power to reach the light.

A single power wire is routed through all three relay contacts. Wiring from the NO (Normally Open) of Relay 1 to the COM (Common) of Relay 2, then from the NO of Relay 2 to the COM of Relay 3, creates a series path that requires every relay to close before the light can activate.

This method can be scaled easily - just continue wiring NO of each relay to the COM of the next relay. Add as many relays as needed to meet your logic or safety requirements.

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Example 5 - AND/OR Logic with Override

This example demonstrates a combined AND/OR logic setup. The light will turn on when:

• Relay 1 AND Relay 2 are both energized
  OR
Relay 3 is energized (override)

This wiring is useful when you need a normal logic condition plus a manual or automatic override option.

For example:
• Relay 1 = night/day sensor
• Relay 2 = motion sensor
• Relay 3 = manual override (local switch)

If it's dark and the motion sensor activates, Relays 1 and 2 energize to turn on the light. But if you want to control the light manually - regardless of sensor conditions - Relay 3 can override the logic and activate the light on its own.

A/D Board Users: The Relay Activator function on any A/D board or ProXR Lite board lets you connect a button or switch to any A/D input. This input can then control the override relay, giving you a convenient local button to manually override the first two relays.

MirC/MirX Users: Add a manual button or switch to trigger the third relay when you need direct control instead of sensor-driven control.

Reactor Users: A local button or switch can be wired to the third relay input to provide a manual override for sensor-based logic.

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Example 6 - OR Logic (Either Relay Activates)

This example demonstrates OR Logic - the light will turn on when either relay is energized. Only one power wire is switched, but it can pass through Relay 1 or Relay 2 to reach the light.

• If Relay 1 activates, the light turns on
• If Relay 2 activates, the light turns on
• If both activate, the light remains on

This setup is ideal when two independent sources should be able to control the same device. Common uses include:

• A timer controlling one relay, with a manual or secondary control for the other.
• Two sensors where either condition (motion detected or low light, for example) should activate the light.

A/D Board Users: The Relay Activator function on any A/D board or ProXR Lite board lets you connect a button or switch to any A/D input. This input can then be used as a manual control of the relay.

MirC/MirX Users: Wire two contact closure inputs into the sender board - either input can trigger the receiver relay to control the light.

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Example 7 - 3-Way Switch (Relay-Based 3-Way Control)

This example shows how to create a 3-way light switch setup using relays. A traditional 3-way circuit allows two switches to control the same light from different locations. In this wiring sample, each physical switch is replaced by a relay - but the operation is the same.

Only one power wire is switched, and the relays toggle the light depending on their current state.

• Activating either relay will toggle the light
• Activating both relays at the same time has the same effect as flipping both switches at once

This wiring method is especially useful because you can replace one of the relays with a physical light switch, giving you both computer control and manual control of the same light. When used correctly, this becomes one of the most flexible and powerful diagrams on the page.

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Example 8 - DC Motor Direction Control

This example demonstrates how to control the direction of a DC motor using two relays. By changing how the motor's leads connect to power, you can run the motor forward, reverse, or place it in a brake state. Braking is achieved by tying both motor terminals to the same power connection, which stops rotation through Faraday's Law.

Relay Operation Summary

• Relay 1 Off / Relay 2 Off → Motor Brake to +
• Relay 1 On / Relay 2 Off → Motor Forward
• Relay 1 Off / Relay 2 On → Motor Reverse
• Relay 1 On / Relay 2 On → Motor Brake to -

The capacitors shown are optional for small motors, but may be required in some situations:

• The induction suppression capacitor prevents the relay from shutting off due to motor back-EMF
• The 0.1µF filter capacitor reduces electrical noise, especially useful when powering sensitive electronics such as radios or amplifiers.

Capacitor Placement
• Place the induction suppression capacitor near the relays
• Place the filter capacitor near the motor
• Additional capacitors may be needed for certain motors

Important Note on Inductive Loads
Motors draw significantly more current at startup than during continuous operation - often 2-3 times their rated running current. For example, a motor rated at 5A (125VAC) may require 10-15A to begin turning. Always select a relay that exceeds the motor's initial inrush current, not just its running current. In this case, a 20-30A relay provides optimal performance and longevity.

Base Station Software

Compatible with All Boards on this Site

Base Station software works by communicating with your controller to identify the model and provides the appropriate graphical user interface for controlling and testing the identified device.  Base Station will assist you in learning how any NCD device functions and will provide valuable diagnostic tools to help determine if your controller is functioning as designed. Base Station software exercises every supported feature of every supported device.  It is the ultimate reference tool for learning, diagnosing, and testing NCD devices.

User Interface

You may click one time on any item in the list to see a graphical user interface that was created as the controller was developed.  Each command set represents a module that is installed in the firmware of your device.

Device Identification

A window will open labeled "Device Identification Data".  This window contains important "Read-Only" information about your device.  Note the "Documentation Related to this Controller" field.  This is a compilation of all articles relevant to your device.  Click on an item in the list to view.  You will need an Internet connection to access this information. All devices released in 2012 and later support Device Identification.

Device Command Sets

Base Station software asks the controller which command sets are supported.  The supported command sets are listed when you run the Base Station software application.  Some controllers may show more command sets while other controllers may show fewer command sets.  The Base Station program will decide which command sets apply to your particular controller.  ProXR users can turn relays on or off and perform any function from the entire ProXR Command Set!

Control All ProXR Functions

Control relays, read status of relays, read inputs all from the ProXR boards and perform all functions of the baord. Base Station is a point-and-click software that will also show you the command that is being sent to the board, making Base Station a great tool for programmers!

Useful Features

There are some useful features to look for when using Base Station Software to control, test, or configure your device:

• Links to Quick Start Guides and Documentation
• Discovers Newtork devices and displays IP Address for easy connection
• Control Command Set Window (circled in red), ProXR users can view commands sent to the board

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Relay Activator

Relay Activator and Analog Inputs

The Base Station Relay Activator control panel allows analog inputs to directly control relays!  Simply connect the analog inputs to buttons or switches and trigger basic relay on or off functions to take manual control of the on-board relays.  The Relay Activator control panel allows you to define 8 functions for each of the 8 inputs.  Functions include turning relays on or off, toggling the state of relays, momentarily flash a relay, momentarily toggle the flashing function of a relay, turn all relays on, turn all relays off, and push notification events.  When push notification events are configured, the controller generates a packet of data every time the inputs change state.

Relay Activator for Manual Control

Relay Activator is great for applications where computer control is used but manual control is necessary at times.  Buttons or switches can be used to take manual control of any of the relays.  You will have the ability to turn a relay on with a computer and turn the relay off with the manual switch! Relay Activator is only available in all ProXR Lite versions and ProXR boards with part numbers begining with ZAD. Download the Relay Activator Quick Start Guide here: in the AD8 Relay Activator Quick Start Guide.

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Reactor Users

Reactor Events Settings

All All Reactor configurations are made through Base Station. Base Station allows users to define the activation of a relay or an event based on the voltage readings of the analog inputs. An input can trigger a relay directly or an input can trigger an event, such as a timer. If an input triggers a relay, the relay may turn on. If an input triggers a timer event, a timer may be started, but a relay may or may not be turned on based on how you have configured the controller (the time delay may be before the relay triggers). The Reactor graphical user interface is only provided when Base Station is communicating with a Reactor board, other functions may not be available with this type of board.

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TaraList Users

TaraList Setup

Base Station Software is used to configure and upload the time schedules to the Time Activared Board. TaraList users will be shown the configuration page for setting up the time schedule and uploading the schedule to the board. ProXR usere will not be offered this page and not see it.

Software Options

Not a programmer and think these boards look great, not to worry we have software to help get you connected and even control the relays with a button on your desktop or by a time schedule!

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Data Sheets & Quick Start Guides

Below are the Data Sheets Quick Start Guides for this board.  These are the guides that will help you communicate and configure this board.