RS232 Pro Series Relay Control
RS232 Relay 2-Channel 5 Amp SPDT
Screw Terminal Relay Connections
Product Code: R25
Connecting the Pro Series to a computer is easy! The R25Pro relay is shown connecting to an optional QS12-F6 Quick Start Kit. A USB to Serial adapter can also be used if you need to connect to a USB port.
Pro Series Relay at a Glance
- 9600 Baud Operation
- Relay Status LEDs
- Control Status of All or Individual Relays
- Quick Connect Terminal Blocks
- TTL RS-232 Inputs
- +12 Volt Operation, 2-Wire RS-232
- Overkill Transistor Drivers
- No-Click Power-up
- 2-Way Communication Capable
- E3C Compliance
Video Resources
(Select a thumbnail to view the video)Introduction to Relay Control

Learn how computer controlled relays communicate and control
Intro to Wired Communications

Learn the basics of wired communications and find the right wired controller for your application
Induction Suppression

Learn about Induction Suppression and how to counter it using Capacitors
Introduction to A/D

Learn about Analog to Digital Conversion and its uses
How to Find the Com Port

Learn how to find the Com Port that your Device is using
About Expansion Ports

Learn about the Expansion Options available to use with our controllers
Resources:
This Product:
Related Products:
Quick Start Kit Available
QS12 Quick Start Kit
Kit includes a high quality regulated switcher supply, serial cable, and RSIO adapter | |
Stock#: QS12-F6 | $49/ea |
Desktop Control
N-Button Lite
Desktop Control & Monitoring
N-Button creates up to 8 desktop widgets to control relays without any programming. Order Today with This Board for Only $29 |
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Stock#: N-Button Lite | $45 |
800-960-4287
417-646-5662
Dual Relay with Quick Connect Terminal Blocks
Control One or Both Relays with Two-Way Communication
Quick Start Kit Available for Easy RS232 Connection
Highly Reliable Relay Board For Demanding Applications
RS-232 Serial Relay Controller
Our RS-232 Relay Boards are fully E3C complaint, allowing up to 256 NCD devices to share a single RS-232 serial port. Mix and match up to 256 devices in any combination. Speak to each device individually or all devices at once.
To control the this Relay Controller, simply connect a data and ground wire between the Relay Controller and computer or microcontroller. Provide +12 Volts DC to the board, and send ASCII character codes to control the relays. The Command Set can be found in the Product Manual.
Even a no-frills design deserves a high-quality driver stage, and that's exactly what we put on our Serial Relay Controllers. Fast-reacting flyback diodes help shunt dangerous voltages away from the driver circuit.
Features include no-click startup, LED status lights, and E3C compliance. Relays can be controlled at 9600 baud and the board is compatible with ANY computer or microcontroller capable of delivering RS-232 data.
Connect this board to the USB port of your computer using a USB to Serial adapter. The USB to Serial Adapter is to be used with the Quick Start Kit and is available at checkout.
Fully E3C Complaint RS232 Relay
Our RS-232 Relay Boards are fully E3C complaint, allowing up to 256 NCD devices to share a single RS-232 serial port. Mix and match up to 256 devices in any combination. Speak to each device individually or all devices at once.To control the this Relay Controller, simply connect a data and ground wire between the Relay Controller and computer or microcontroller. Provide +12 Volts DC to the board, and send ASCII character codes to control the relays.
Even a no-frills design deserves a high-quality driver stage, and that's exactly what we put on our Serial Relay Controllers. Fast-reacting flyback diodes help shunt dangerous voltages away from the driver circuit.
Features include no-click startup, LED status lights, and E3C compliance. Relays can be controlled at 9600 baud and the board is compatible with ANY computer or microcontroller capable of delivering RS-232 data.
NCD Component Library
Fully functioning programs for R25, R210, R220 and R230 are included with the NCD Component Library. With the NCD Component Library we've "started" the programming for you. We say started because these are fully functioning samples but we've also included the source code so you can customize them to your exact needs. The NCD Component Library is a plug-in for the Visual Studio 2005/2008 that greatly simplifies the communications to the NCD product line. The samples can be run in Visual Studio and fully customizable to your needs. Two different dual channel samples are available to turn on and off the relays, read the status of the relays and retrieve startup default state of relays. To view screen shots of each sample visit our NCD Component Library Page. Start by downloading the FREE NCD Component Library and you will be communicating with any NCD device faster that ever!
![]() The above sample demonstrates control and status read of 2 Relays. Compatible with all R2x RS-232 Series Relay Controllers. |
The above screen shot shows one of two fully functioning dual channel samples that are available with the NCD Component Library. View all the examples on our NCD Component Library Page. |
Desktop Relay Control
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.Relay Button widgets turn relays on/off directly. It has never been so easy to control relays before. | |||
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Relay Status widgets show status of the relay automatically right on the desktop! | |||
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N-Button Lite is available as a free download. Look for the Desktop Control section to the right to download.
N-Button Lite version supports up to 8 widgets. If you want to add more than 8 widgets, you need upgrade to the standard version.
Save 40% on N-Button TodayLimited time offer! Order the N-Button Lite with a relay board and get it for the unbelievable price of just $29.00. That's a discount of 40% off the retail price! If you purchase the full N-Button it's just $99.00 with the purchase of a relay board and that's a 41% savings off retail price! Desktop control, sensor meters and backgrounds plus all the customization for just one low price, purchase your copy of N-Button Lite today.
Quick Start Kits
Also available is our QS12-F6 Quick Start Kit. Kit includes a high quality regulated switcher supply, serial cables, and an RSIO adapter board used to add a standard serial and power connector to this relay controller.
Resources
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NEW TO RS232 COMMUNICATIONS? GET STARTED HERE Click the above link for an exclusive article on RS232 Communications |
RS232 Relay Article | RS232 Relay Article |
NCD Base Station Software |
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Download Manual | Download the 2 Channel RS232 Product Manual |
E3C Complient | Download E3C Complient Specs |
Download VB Samples | Download VisualBasic 6 Example Source Code |
NCD Component Library | The NCD Component Library is a Plug-In for Visual Studio 2005/2008 that greatly reduces software development time, effectively reducing most control operations to a single line of code. This free download includes four example applications compatible with the Pro Series. |
Wiring Diagrams | These wiring diagrams will help you understand how to connect to your devices and use relays as a form of control logic |
Mechanical Drawing | Mechanical Drawing for this board |
2-Channel 5-Amp Relay Board