Contact Closure Over IP

Some Setup Required

The MIRCR430_MCNET are sold in pairs, you will receive both boards shown here when you purchase this set.  These boards will allow you to control a relay over your Local Area Network using a dry contact (no voltage) input.  There will be some setup to pair the boards together.  Using the free NCD5500 Configuration software one board will be setup as a server and one as the client, it doesn't matter which is which.  In the Client Board you will set the IP address of the Server Board which will marry them together.  Dry Contact (no voltage) inputs on the sender board controls the relay on the receiver board.  When the dry contact circuit on the sender board is closed the relay on the receiver board is energized or on, when the circuit opens the relay turns off.

LAN Connection Only

Please Note these boards do not work over an internet connection, both boards must be on the same Local Area Network.  Also both boards will require an assigned static IP address.  We recommend that you assign the boards with IP addresses outside the DHCP range of your network router.  Each board will utilize a static IP address.  One board will act as the server while the second board will act as the client.  The connection between the two boards is via a TCP socket and the port number used by this TCP socket is arbitrary and can be configured to any port you wish!  In our setup we used port 2101.  This may be important information if the boards are on separate subnets.  Relay Pros or NCD is not capable of providing technical support for complex networks, this should be handled by the Network Admin.

Windows Based Setup

Setup will require a Windows computer connected to the same network as the boards using configuration software, a free download.  Initially both boards will be in DHCP mode so a managed network is required, at least for initial configuration.  It is not possible to configure these devices on an unmanaged switch, however after configuration is complete it is absolutely possible to install the boards on an unmanaged network.

Location Is Not an Issue

MirC boards with an Ethernet connection should be used in applications where wireless or a wired installation is not an option.  Location is not an issue as long as both boards are on the same network.

Multiple MirC Pairs

Multiple pairs of the MirC Controllers can be used on the same network.  The boards are paired together using the MAC Addresses of the Ethernet modules installed meaning multiple pairs will not interfere with each other! 

Induction Capacitors

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 these boards requires the use of induction suppression capacitors 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 electrically interfere with the microprocessor logic of the boards, causing relay banks to shut down unexpectedly.  If this happens the boards may need to be power cycled to restore communication.  Capacitors are available at checkout, for more information and drawings view our Induction Suppression Page.

MirC Board Features

MirC Relay

This pair of boards allows you to control a relay using a dry contact (no voltage).  The dry contact can come from a manual switch, a sensor or device that provides a contact closure, or another relay.  As long as the contact closure circuit is closed the relay will remain energized or on.  When the circuit opens the relay will de-energize or turn off.  Meaning the relay will respond to a toggle or momentary connection depending on what type of input you select.  Each MirC pair is ready to stand up to rigorous demands from heat, cold or vibration.  Take it from us, these controllers will hold up!

Status of Remote Relays

Both boards are also equipped with LEDs that display the status of the relay.  Status information is verified using 2-way wireless communications.  If communication is lost between the devices, the LED will turn off.  Additionally, every MirC controller is equipped with a Busy/Ready LED.  If the Busy LED flashes, this indicates the other device has successfully received and accepted your contact closure status.  If the Busy LED does not flash, the remote device is out of range.

What Happens When Communication is Lost

A common question we receive is what happens to the relay that is energized when communications between the boards is lost.  The relay can remain energized or on until communication is re-established or the relay can de-energize or turn off.  This is done by a simple jumper on the board and setting it to Beacon or Smart mode.  Regardless of the Mode you choose, if the busy LED flashes, the two devices are communicating properly.  If the Busy LED does not flash at all, the devices are unable to communicate.  See the table below for the differences between Beacon and Smart mode.

Contact Closure Inputs

The inputs on these boards accept a dry contact only - no voltage.  Users must never apply any voltage to an input on either of the MirX Controllers.

Relay Outputs

Relays do NOT provide a voltage output and can be used as a dry contact.  They provide a contact closure output and simply interrupt the power to the device you are switching.  The relays are rated for 240 VAC or 24 VDC.  See the Data Sheets tab above for the specs on relays installed.

SPST Relay Installed

This board has SPST relays installed.  SPST Single Pole Single Throw Relays simply connect two wires together.  The Common (COM) is the moving part of the relay that comes in contact with the Normally Open (NO) when the coil to the relay is energized.  Wiring is done directly to the Relay terminals using a common 1/4" quick disconnect terminal.  To the right is a picture of the connector that will connect to the relay.

2-Million Cycles

MirX 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.

Break-A-Way Tabs for a Smaller Design

The MirC relays have a great feature where space is a premium - Break-A-Way Tabs. The Break-A-Way Tabs allow most boards to fit in an optional undrilled plastic enclosure.  Snap off the Break-A-Way Tabs and you have a controller with a smaller profile when you need to fit in a tight space.

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.

5-Year Warranty/Money Back Guarantee

MirC 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. 

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.

Contact Closure 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

• Single Pole Single Throw Relays Installed
    - Wire to the Normally Open Position
• Wire Directly to the Relay Using 1/4" Quick Disconnect Terminal
• Break-A-Way Tabs Lets you Decide the Board's Size
• Temperature Rating -40° C to 85° C
• RoHS Compliant

MirC Features

• Control Relay from a Dry Contact (No Voltage)
• Inputs on Sender Board Control Relays on Receiver Board
• Sender Board Displays Status of Remote Relays

MCNET / MXNET Setup

Before You Start (Requirements)

It should be noted that these boards do not communicate over an internet connection.  Both boards must be on the same LAN.  Also both boards will require an assigned static IP address.  We recommend that you assign the boards with IP addresses outside the DHCP range of your network router.  If you are connecting these devices to an IT managed network it is recommended that you review this guide with the Network Administrator prior to proceeding.

Static IP Required

Each board will utilize a static IP address.  One board will act as the server while the second board will act as the client.  The connection between the two boards is via a TCP socket.  The port number used by this TCP socket is arbitrary and can be configured to any port you wish.  In our setup we used port 2101.  This may be important information if the boards are on separate subnets.  Relay Pros or NCD is not capable of providing technical support for complex networks, this should be handled by the Network Admin.

Windown Configuration

We will be using configuration software which requires Windows so a Windows computer connected to the same network as the boards will be required.

Managed Network Required for Setup

Initially both boards will be in DHCP mode so a managed network is required, at least for initial configuration.  It is not possible to configure these devices on an unmanaged switch, however after configuration is complete it is absolutely possible to install the boards on an unmanaged network.

Configuration

Initial setup

• Download and install the NCD5500 configuration software available here: NCD 5500 Configuration Software.
• Connect standard Ethernet cables to the boards and plug them into the network. Then power the boards up using a regulated 12VDC power supply source.
• Open the NCD5500 Configuration software.
• Click the Search Button in the Configuration software until you have discovered both boards.  You will see them listed by their MAC address.  This Mac address is also printed on top of the Ethernet module installed in the board.  This information can be used to differentiate between the two boards.

First board Configuration (Server)

• Click on one of the boards to open it’s settings.  All settings we will be covering will be under Basic Settings.  We do not need to do anything under Advanced Settings.
• Set the baud rate to 57600.
• Change the Network Settings Radio button to Use the Follow IP address.
• Enter a Static IP address for the board into the IP address field, and enter information into Subnet Mask, Gateway, and DNS Server as per the requirements of your network.
• If you would like this board to act as the Server(does not matter which board you choose to act as the server) then Under Connection set Work As to TCP Server. Set the Local Port field to any port you wish other than 80. This will be the port the module listens for incoming TCP Socket connections on. This information is applicable if there are any firewalls. For our setup we are using port 2101.
• Click Apply Settings.

Second Board Configuration (Client)

• Click on the other board in the list to open it’s settings.
• Set the baud rate to 57600.
• Change the Network Settings Radio button to Use the Follow IP address.
• Enter a Static IP address for the board into the IP address field, and enter information into Subnet Mask, Gateway, and DNS Server as per the requirements of your network.
• This board will act as the Client and will connect to the previous board we configured.   Click the Work As Drop down menu and change it to TCP Client.  Do not worry about the Local Port Setting as it does not apply.
• Enter the Static IP address entered for the first board acting as the server into the Remote Host field.
• Enter the Port number entered as the Local Port on the first board acting as the Server into the Port field to the right of the Remote Host Field.
• Click Apply Settings.

Final Testing

Both boards should now be configured and should work.  You can validate that the boards have a valid TCP socket connected by checking the Red LED on the Ethernet module adjacent to the metal Ethernet Jack.  If it is on solid then the connection is established between the boards.  You may also monitor the Busy/Ready LEDs on the boards which should flash on/off periodically indicating the boards are communicating.  You may now close the inputs on the boards and should see the relays on the remote unit turning on/off.

Power & More

20/30 Amp Relay Board Specifications

This table covers all NCD boards with 20 or 30 amp relays installed.  All ratings assume 12VDC operation at 70°F (21°C).  Please note that most ratings are estimated and may be subject to periodic revision.  Some ratings represent stock controller settings without performance enhancement optimizations.  The estimated processing time can be impacted by background services and choice of commands.  Standby power consumption assume no communications module is installed and no relays are active on the controller.  Please add the power consumption of the activated relays and communications module to obtain a better estimation of power consumption.

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			15ms	Needs Further Validation
Relay Deactivation Time			10mS	Needs Further Validation
Operational Life Mechanical	10,000,000			Component Operation Rating
Operational Life Electrical	100,000			Component Rating at Maximum Load

Communication Module Specifications

This table covers all NCD Communication Modules.  While NCD communication modules operate at 3.3VDC, the ratings below highlight the effect they will have on the master controller operating at 12VDC at 70°F (21°C).  Maximum ratings should be used for power budget planning purposes and may reflect short term absolute maximum peak current consumption.  Some ratings are estimated and subject to periodic revision.

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

AD8 Analog Input Usage Notice

Analog Inputs should not have a voltage present when powered down.  Use a 220 Ohm current limiting resistor on each input to prevent damage to the controller if voltage will be present on the analog input when this controller is powered down.  Do not exceed 0 to 5VDC on any analog input or the on-board CPU will be damaged.  Most analog inputs include a 10K Pull Up/Down resistor to help keep the inputs quiet when not in use.  This 10K resistor may slightly bias the readings of some sensors.

Accessories

Relay Logic

Relay Wiring Samples

This page demonstrates several simple ways to wire a relay or multiple relays for various applications. We use the example of switching a light but the light can be swapped for a gate control, security system, dry contact output and other devices. These examples show different ways to wire to a relay or multiple relays to produce a desired effect.
Get a printout of this page

SPDT Wiring

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 and we have examples below.

SPST Wiring

SPST Single Pole Single Throw Relays have two connections - Common and Normally Open. The Common (COM) is the moving part of the relay that comes in contact with the Normally Open (NO) when the coil to the relay is energized. The only SPST relay we sell on this site is the 30-Amp relays, The wiring examples below can be used with the 30-Amp relays as long as the example doesn't use the Normally Closed position.

DPDT Wiring

A single DPDT Double Pole Double Throw 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 devices to be switched at one time. In effect, there are two independent switches on a single DPDT relay - they will always switch together. There are two connectors with Normally Open, Normally Closed and Common for each relay allowing two separate connections. Wiring using these examples can be the same as any SPDT relay.

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Relay Logic Examples

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Example 1 - Simple Off/On

This example demonstrates how a relay can be used to activate a light bulb. When the relay turns on, the light comes on. Only one power wire is switched with this example using the COM (common) and NO (normally open) connections of a relay. This is the simplest of the examples, switching a light in this example or any device on when the relay is energized.

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Example 2 - Simple On/Off

This example demonstrates how a relay can be used to turn a light bulb OFF.  When the relay is energized the light turns off, when the relay is off the light will be ON.  Only one power wire is switched in this sample using the COM (common) and NC (normally closed) connections of a relay. Not commonly used but great for applications where the device is on most of the time so the relay doesn't have to be energized to to keep the device on. Power cycling a device can be a typical use for this wiring, when the relay turns on the device is powered off.

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Example 3 - 2 Relays to Activate

This example demonstrates how two energized relays are required to activate a light bulb. This is the same as a Logic and function because Relay 1 AND Relay 2 must be on to activate the light. Only one power wire is switched in this example using two relays to turn on the light. This example would be used if you want two parameters to be active before the light will switch on. If you have sensors or need two parameters to be in the correct state before the light turns on. A quick example would be a light sensor will need to show it's dark and a motion sensor showing someone in the room before the light will turn on.

MirC/MirX Users: Two contact closure inputs in the sender board required to control a device. Use this wiring when you require two outputs to close before you switch the relay.

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Example 4 - 3 Relays to Activate

This example demonstrates how three energized relays are required to activate a light bulb. Just like example 3, Logic and function play a roll because Relay 1 AND Relay 2 AND Relay 3 MUST be energized to activate the light. Only one power wire is switched in this example using three relays to turn on the light. Simple wiring from the NO of Relay 1 to the COM of Relay 2 to the NO of Relay 2 to the COM of Relay 3 will require that all three relays would need to be energized to turn on the light. This can be expanded to include as many relays as needed as long as you wire NO of the first relay to COM of the next relay.

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Example 5 - Override Function

This example demonstrates the and/or function. The light bulb will be activated if Relay 1 and Relay 2 are energized OR if Relay 3 is energized. This example is great for applications that may require a logical condition of 2 relays plus an override feature. For instance, if Relay 1 is a night/day sensor, Relay 2 is a moisture sensor. If its dark and the soil is dry, Relays 1 and 2 can activate a pump. If you want to override these conditions with local physical switch using Relay Activator function (see the AD8 Command Set Tab) Relay 3 would override Relays 1 & 2.

MirC/MirX Users: Add a manual button or switch to control the third relay to manually control the light if you have sensors that control the other relays.

Reactor Users: Add a manual button or switch to control the third relay to manually control the light if you have sensors that control the other relays.

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Example 6 - Either Relay Activates

This example demonstrates how either relay can be used to activate a light. Only one power wire is switched in this example using either of two relays to turn on the light. In this sample, only one activated relay is required to activate the light. If both relays are activated, the light will be on. Great for if you have a timer for one of the relays but want to turn the light on when the timer is scheduled off or have two sensors connected and want either of them to control a device.

MirC/MirX Users: Two contact closure inputs in the sender board and either of the inputs can control one light or device.

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Example 7 - 3-Way Switch

This example demonstrates how to create a 3-way light switch to activate a light. A 3-way light switch is where two light switches can be used to activate a single light. This sample is exactly the same as a 3-way light switch, the only difference being each physical switch is replaced by a relay. Operationally, it works the same way. Only one power wire is switched in this example using both relays to turn on the light. Each relay activation will cause the light to toggle. Switching two relays at one time is like flipping 2 switches at once....with the same result. This sample is particularly useful since you can replace one relay (as shown in the diagram) with a physical light switch. This will allow a computer to control a light as well as manual operation of a light. Properly used, this can be one of the most valuable diagrams we offer on this page.

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Example 8 - Motor Control

This example demonstrates how to control the direction of a DC motor using 2 relays. Braking is accomplished by connecting both motor terminals to a common power connection (Faraday's Law). The capacitors shown may not be required for small motors, but if you experience problems with relays shutting themselves off, the induction suppression capacitor will be required. The .1uF capacitor helps suppress electronic noise if the battery were to be used by sensitive devices (such as radios/amplifiers).

• Relay 1 Off Relay 2 Off = Motor Brake to +
• Relay 1 On Relay 2 Off = Motor Forward
• Relay 1 Off Relay 2 On = Motor Backward
• Relay 1 On Relay 2 On = Motor Brake to -
• Induction Capacitor Should Be located by relay
• Filter Capacitor Should be Located Near Motor
• Additional Capacitors May be Desirable for Some Motors

Inductive loads typically require 2-3 times the runtime voltage or amperage when power is first applied to the device. For instance, a motor rate at 5 Amps, 125 VAC will often require 10-15 amps just to get the shaft of the motor in motion. Once in motion, the the motor may consume no more than 5 amps. When driving these types of loads, choose a relay that exceeds the initial requirement of the motor. In this case, a 20-30 Amp relay should be used for best relay life.

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.