Beacon Mode:

In beacon mode, the relay status will not change if communications is lost between the relay controller and the sender. Beacon mode is ideally used in applications where it is safe for relays to stay on in the event of a communication failure.

Smart Mode:

In smart mode, the relay will turn itself off automatically if communications is lost between the relay controller and the sender. Smart Mode is ideal for applications where it may not be safe to leave a relay on in the event of communication loss with the remote device.

Fiber Optic Compatibility

MirC_ZRS Series Controllers are compatible with Fiber Optic Converters that support RS-232 communications at 1200 baud. Additional Baud rates can be customized for faster communications speeds. Adapters are available for fiber optic MirC applications, please contact us prior to ordering if you need to use MirC controllers in a Fiber Optic application.


MirC_ZRS devices are only sold as a permanently married pair, pricing shown on our web site indicates pricing for the pair of controllers. Contact Closure Inputs may only be connected to switches, buttons, or sensors with Contact Closure capability. Not suitable for use in voltage detection applications. MirC_ZRS devices use RS-232 two-way Serial communications to ensure the remote device is properly functioning. The Busy LED is always used to indicate a properly functioning remote device. If you do not see the Busy LED flash, then the MirC_ZRS controller is unable to communicate to the remote device. A flashing busy LED is your verification that all communications are functioning properly between MirC_ZRS controllers.

Customers who require inductive switching (such as motors, lights, pumps, solenoids, and Transformers) should visit the Induction Suppression portion of our web site.


The distance between MirC controllers will affect reliable operation. With this RS232 version you should expect to get a range of 1000 feet using a 3 wire wire cable.  The cable can be a Cat5, Cat6 or standard telephone cable.  The wires will connect directly as shown in the photo above and must be secured using screw terminals.

Communications Variations:

Wireless MirX Controllers

MirX Controllers are also available in a wireless version. You can expect wireless MirX devices to function properly in most applications between 300 feet and up to 15 miles depending on communications module and antenna options chosen. Visit the Wireless MirX page for more information.

Product Variations:

MirC and MirX Series Pairs

NCD Currently offers 2 variations of this design: MirC and MirX.

MirC: Transmitter Controller and Receiver Controller. The Transmitter Shows the Status of Relays on Receiver Controller. The Transmitter is equipped with Contact Closure Inputs and Remote Relay Status LEDs. The Receiver is equipped with Relays and Relay Status LEDs.

MirX: Each Controller is a Transmitter and a Receiver. The Inputs on One Controller control the Relays on the Opposite Controller. Relay Status is Shown using LEDs on Each controller.

MirC controllers include two circuit boards. The "Local" and "Remote" circuit boards work together to control relays at the remote location from the controller in the Local location. The Local Circuit board has contact closure inputs. When an input change is detected on the Local circuit board, the relay is changed on the Remote circuit board. The Remote Circuit board sends feedback to the Local controller. The LEDs on the Local controller display the status of the relays in the Remote location based on 2-way communications. If communications is lost between the devices, the Remote relay will turn off (If set to Smart Mode). The relay status LED on the Local controller will also turn off. The Remote relay controller is also equipped with LEDs to show the status of the relays. Relay status can be seen on BOTH controllers.

MirX controllers also include two circuit boards. Each controller is a Transmitter and a Receiver, each controller is equipped with contact closure inputs and relays. The local contact closure inputs control the relays at the remote location and vice versa. The LEDs on each controller display the status of the relays ONLY.

Ethernet Network MirX Controller

Ethernet Network MirX Controllers allow communications between two MirX controllers over a Local Area Network (LAN) or over the Internet for use in world-wide switching applications. Please visit our MirX Ethernet page for more information.

Attention: No Voltage Input

Please Note: Users must NEVER apply any voltage to an input on the Mir-C controller, these inputs are for Contact Closure connections only.