The Key Fob Interface

Easy Key Fob Control

If your application needs wireless relay control, our Key Fob Relay Series delivers the most powerful and flexible solution on the market. These are not simple "one-function" remotes - our Key Fob boards are designed for advanced control.
Configure each button to operate relays in almost any way you can imagine.

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Key Fob Functions

A single button press can do far more than basic on/off control. Most users configure buttons for toggle or momentary actions:

• Toggle: Press once to energize the relay, press again to turn it off.
• Momentary (Press & Release): Relay energizes while the button is held, and turns off when released.
• Relay Timer: Control for a duration of time, turns off after predetermined time

These options can be preconfigured before your board ships.
Need more? The Key Fob system supports relay grouping, timed events, flashing commands, and other advanced actions. One button can control multiple relays or energize a relay for a preset duration. We can preconfigure advanced functions as well but reccommend purchasing a Configuration Kit to make any adjustments in-house without sending the board back to us.

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Key Fob Range

MS-Series Key Fobs offer a rated range of 750 ft (228 m).
The MS 8-Button Key Fob with external antenna extends the range to 1,000 ft (304 m).

Range varies by environment - maximum distances are achieved outdoors with clear line-of-sight and minimal interference.

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ZigMo Configuration Kit

KFX Receiver Modules are configured through Base Station Software and must be plugged into a ZIGMO Configuration Board during setup. The KFX Module is only installed in the Configuration Kit during setup - after that, it goes right back into your board. Only one ZIGMO is required no matter how many receivers you use.

The ZIGMO provides the connection between your computer and the KFX Module, allowing you to set Baud Rate, define Data Bytes, and customize the actions for each button press.
The ZIGMO is included in the KFX Integration Kit and available during checkout.

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Easy Configuration

Your board includes a KFX Communications Module, enabling full key fob control.
Setup is done through Base Station Software - a free, point-and-click configuration tool. Assign the exact command you want each button to send using a simple numeric command structure.

Prefer us to handle it? Just choose toggle or momentary at checkout and we'll configure it before shipping.
Key Fob Configuration

Common Commands

Here are some of the most frequently used Key Fob actions:

• Toggle and Momentary Commands
• Turn Off All Relays Then Turn On a Specific Relay
• Relay Timers: Relay Energized for a Specific Time
• Relay Pulse Commands
• Relay Grouping: Controlling Multiple Relays Together
• Relay Flashing Commands

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Pair Up to 40 Key Fobs

Each KFX Receiver can pair with up to 40 key fobs (1, 2, 4, and 8-button models available at checkout).

All paired key fobs perform the same actions. Individual button functions cannot be uniquely assigned per remote - every paired key fob mirrors the same command structure.

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Who’s Qualified to Use the Key Fob Series?

You don't need programming experience - just basic computer skills.
Simple functions are easy to configure, while advanced sequences may require a little patience and understanding of how the commands operate.

Base Station Key Fob Configuration

Key Fob Configuration

The FX Receiver Module is configured using Base Station Software (free download). During setup, the module simply plugs into the ZIGMO Configuration Board. One ZIGMO is all you eed - no matter how many KFX Receivers you plan to configure.

The ZIGMO serves as the communication bridge between your computer and the KFX Module, allowing you to set Baud Rate and define the Data Bytes sent for each key fob button press. The ZIGMO is included with the KFX Configuration Kit and is available at checkout.

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Free Setup Software

Your board can ship preconfigured with toggle or momentary operation at no charge.
For custom commands, use the Key Fob Configuration Kit and Base Station Software to program the KFX Module. After configuration, the module is placed back into your board and is ready to transmit your programmed commands each time a button is pressed.

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ZigMo Configuration Kit

KFX Receiver Modules are configured through Base Station Software and must be plugged into a ZIGMO Configuration Board during setup. The KFX Module is only installed in the Configuration Kit during setup - after that, it goes right back into your board. Only one ZIGMO is required no matter how many receivers you use.

The ZIGMO provides the connection between your computer and the KFX Module, allowing you to set Baud Rate, define Data Bytes, and customize the actions for each button press.
The ZIGMO is included in the KFX Integration Kit and available during checkout.

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Configuring the Buttons

When you program a button, you're configuring the command the KFX Module will send to the board when that button is pressed. Using Base Station Software, you can assign simple toggle actions or advanced commands with delays, pulse patterns, or timed operations.
The KFX Module supports both button-press and button-release events for even greater flexibility.

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Common Commands

Here's a brief list of some of the more common commands used when a button is pushed on the key fob.

• Toggle and Momentary Commands
• Turn Off All Relays Then Turn On a Specific Relay
• Relay Timers: Relay Energized for a Specific Time
• Relay Pulse Commands
• Relay Grouping: Controlling Multiple Relays Together
• Relay Flashing Commands

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KFX Module

Every Key Fob Relay board is equipped with a KFX Communications Module, adding full wireless key fob capabilities. The module is powered directly from the board.
The board itself requires 12VDC, which can be hardwired or supplied using an optional wall-wart power supply available at checkout.

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Data Sheets & Quick Start Guides

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Key Fob Board Features

Key Fob Relay

This tab highlights the design and build quality of the Key Fob ProXR Lite Series. Each controller is machine-manufactured for precision, durability, and long-term reliability. Every board is fully tested before it leaves the production facility, ensuring it can handle tough environments - heat, cold, vibration, and continuous daily use.

Our best proof? Thousands of these boards are operating in real-world applications all over the globe. These controllers are built to last.

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Full ProXR Enhanced Firmware Installed

This board includes the full ProXR Firmware, giving you access to the complete ProXR Command Set - just without expansion capability. These commands let you assign each key fob button to a specific relay and define exactly how each button behaves.

Configure simple actions like:

• Toggle: Press once to turn a relay on, press again to turn it off
• Momentary: Relay energizes while the button is held
• Relay Timer: Control for a duration of time, turns off after predetermined time

These options can be preconfigured before your board ships.
Or program more advanced behaviors such as relay grouping, relay flashing, press-and-release actions, and other custom sequences. The ProXR firmware gives you full control over how your key fob operates the board.

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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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Key Fob Relay 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
• Surface mount allows for a smaller more reliable board
• Break-A-Way Tabs lets you decide the board's size
• Screw terminal or direct relay connections makes connecting to the board easy
• Board Powered by Barrel Connector or Screw Terminal

Key Fob Features
• 40 Key Fobs can be paired to a single board
• Each Key Fob can be paired to multiple boards
• 750' (228 Meter) or 1000' (300 Meter) Range

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.

Get a printout of this page

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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.

Data Sheets & Quick Start Guides