DMXmrx Miniature Wireless DMX Receiver User Manual


Radio Frequency Compliance

RC4Magic operates in the 2.4GHz ISM band, which is harmonized for use worldwide.  Additional information is provided in the Specifications section of this manual.



Harmonized Design for a World of Choices

RC4 Wireless has been making the world’s most popular low-voltage wireless dimmers since 1991.  Today, RC4 offers the first and only fully harmonized cross-platform wireless DMX and dimmer framework that is compatible with all leading wireless DMX data protocols worldwide: RC4MagicTM, RC4Magic-900TM, Lumen Radio CRMXTM, and Wireless Solution W-DMXTM.  With only minor hardware differences between families, and a nearly identical user-interface across all RC4 Series-3 Harmonized Design devices, a new standard is set for ease-of-use and range of features.

This manual is for RC4MagicTM Series 3 DMXmrx Miniature Wireless DMX Receiver, including specific details pertinent to RC4Magic Unique System IDs, and RC4MagicPCTM remote configuration software.


RC4MagicTM Series 3

First launched in 2006, RC4Magic is widely considered the most popular wireless dimming system in theatre.  The new Series 3 system introduced in 2014 won a PLASA London Award for Innovation in that same year.


RC4Magic DMXmrx
Wireless DMX Receiver

Wireless DMX

The DMXmrx is the functional equivalent of a DMXio transceiver in receiver mode.

Any number of DMXmrx receivers can be used. Thus, a multi-unit RC4Magic Series 3 system can take the place of splitters, isolators, and distribution boxes, providing superior electrical isolation while eliminating unsightly wiring.

RC4Magic devices work reliably to 300 feet or more outdoors, and marginally less indoors.

The wireless data from a DMXio transmitter can also be received by RC4Magic wireless dimmers, including RC4Magic Series 3 DMX2dim, DMX4dim, DMX4dim-500, DMX2micro, DMXi2c, and DMXfb.  In fact, the DMXmrx is simply a DMX2dim without the dimmers.

Data Privacy and Security

Each RC4Magic Series 3 system is programmed with three unique and private system IDs. RC4 IDs serve as system identifiers and encryption keys, ensuring interference-free operation anywhere, anytime. Every RC4 user and project has their own IDs. Private IDs are shared only by explicit request with a written agreement between all parties involved.  (Wireless DMX systems made by others give you selectable channels or IDs, but they are the same options for everyone; that is not the case with RC4Magic.)

RC4Magic divides the 2.4GHz rf spectrum into 12 individual channels.  Using DSSS (Direct Sequence Spread Spectrum) each channel transports a full 512-channel DMX universe.  By default, RC4Magic transmitters scan the 2.4GHz band and find the quietest channel.  Thus, your system may not be operating on the same channel every time you use it, but it will always be on the best channel.  If your situation demands more controlled spectrum management, RC4MagicPC software allows a specific channel or range of channels to be allocated.  Receiver devices scan to find the associated transmitter with the correct ID.

Multiple RC4Magic Series 3 systems using different IDs and channels can operate at the same time in the same space, and each system will provide a separate wireless DMX universe on its own private wireless network.  In a space with little or no other radio activity, there is enough bandwidth for 15 full-speed RC4Magic systems, each with any number of receivers and dimmers.  The ability to select channels within the spectrum also allows other critical systems in the same band to be avoided.

One wireless DMX universe with up to 512 channels uses one RC4Magic system ID.  A DMXio transmitter on a separate ID is required for each different wireless DMX universe you use.  Thus, 4 System IDs provide 4 individual wireless universes, provided you have enough RC4Magic hardware to make use of them.  You can add RC4Magic devices to your system at any time – just tell us your System IDs when you order.

DMX Data Connections

Because of its small size, the DMXmrx uses a non-standard female miniplug  as the DMX connection.  An adaptor from miniplug to female XLR5 is provided with the unit and is compliant with USITT DMX512/1990.

Custom cables can be made using this pin-out:

3.5mm Receptacle DMX XLR (3 or 5 pin)
Data B / Data – Tip 2
Data A / Data + Ring 3
Common Sleeve 1


The DMX data output is plug and play and precisely reproduces the DMX signal being transmitted by the associated DMXio transmitter.  The number of channels in the DMX universe and the frame rate are determined by the data input at the DMXio.  The DMXio includes the ability to mask or limit channels, as well.  None of these parameters are user adjustable in the DMXmrx receiver.

If some channels are not being received, check the settings in the DMXio transmitter.

DMX Termination

The DMXmrx provides the recommended termination for an RDM bidirectional device.



Power Requirements

The DMXmrx is intended for mobile application, typically in costumes and small props.  The power connections are screw terminals for DC power input and are labeled for +/- polarity.  The internal switching regulator works efficiency over the wide input range of 6V to 35VDC.

The power input is protected against reverse polarity.  Note however, that if power is applied in reverse while a DMX connection is present (via the miniplug), a severe ground differential may result that could damage either the DMXmrx or connected equipment.  RC4 Wireless accepts no liability for such damage.  Be careful when connecting power.

Current draw of the DMXmrx is low – just 0.4W.  Power can come from a wall transformer with bare leads for connection to screw terminals, or from external batteries.  A pack of five (or more) AA or AAA batteries, or even a small 9V battery can be used.

Signal Range and Antenna Options

In many cases, the DMXmrx will deliver reliable and acceptable performance up to 300 feet from an optimally located DMXio transmitter.

When operating outdoors, place the transmitter (or the transmitter antenna) above people’s heads and above other obstructions.  Line-of-sight is not required for RC4Magic, but dense objects between devices — like concrete walls — will attenuate the radio signal and reduce the available range.

For longest possible range, use a DMXio-HG transmitter with a high-gain and/or directional 50-ohm antennas.

Restore Defaults

If the user settings have been changed, you might want to restore everything back to defaults when setting up for a new project.  This is easily done by pressing two buttons together:  Hold the Func button, tap the ID0 button, and release the Func button.  The device will restart, which may take up to 6 seconds.

Power-Up Button Functions

If a button is held down during DMXmrx power-up, then a power-up “hidden” function is invoked.  These are for selecting an RC4Magic System ID, or enabling the RC4 CodeLoader for firmware installation.

All RC4 users and projects are assigned three unique private system IDs.  The IDs programmed into your units belong only to you.  Most RC4Magic systems operate on ID0 (zero), the default setting when shipped.  There is no need to change this setting unless you are using multiple wireless DMX universes.  Each separate ID supports a separate and unique wireless DMX universe, independent and different from all other RC4Magic users.

ID0 (zero)

Private and Unique RC4 System ID0 (zero) is selected if the ID0 button is held during power-up.  This is the default ID selection for new devices, and after Restore Defaults has been invoked.


Private and Unique RC4 System ID1 is selected if the ID1 button is held during power-up.


Private and Unique RC4 System ID2 is selected if the ID2 button is held during power-up.

ID3 Public

The common and non-private ID3 is selected if the ID3/Public button is held during power-up.  ID3 is the Public ID and is the same on all RC4Magic Series 3 devices ever built.  This allows devices from different systems, owned by different people, to be used together.  It also ensures that when set to this ID any RC4Magic device can be accessed for configuration, even if numerous parameters have been changed.

The Public ID is also used when initially setting up RC4MagicPC with a remote control dongle or with a RC4Magic Series 3 device in Dongle Mode.  Until your computer has connected to one of your devices and learned your unique system IDs, it does not know what they are.  After learning, RC4MagicPC software securely stores your Private IDs on your PC.

LED Indicators

RF Data – Yellow

This indicator blinks on receipt of RF packets.  When many DMX channels are changing rapidly, blinking is fast and shimmery; when channels are in a steady state, blinking is somewhat slower.  Irregular or inconsistent blinking often indicates drop-outs caused by a poor RF connection when, for example, devices are too far apart.

On power-up, this is one of two LEDs that indicate the selected RC4 System ID.
Selected ID Indication at the end of this section.

COP  – Green

COP means computer operating properly and is indicated with a slow cyclical blink.

If the RC4 CodeLoader feature is enabled on power-up, the COP indicator will remain solidly on for 5 seconds.  If CodeLoading does not commence within those 5 seconds, normal device operation proceeds.

On power-up, this is one of two LEDs that indicate the selected RC4 System ID.
Selected ID Indication at the end of this section.

RF Connect – Blue

When this indicator is continuously on, without blinking, the RF receiver is NOT connected to a wireless network.  In this state the radio is scanning through RF channels searching for valid data encoded with the selected RC4 System ID.  Every few seconds this indicator will briefly flutter to indicate the scanning process is restarting. When a transmitter with matching ID is found, this blue indicator will steadily and continuously blink to indicate it is wirelessly connected.  This indicator must be blinking steadily during normal operation.

Selected ID Indication

On power-up, the DMXmrx indicates which RC4Magic System ID is selected with a series of blinks on the two left-most LEDs.  (The patterns are the same on all RC4Magic Series 3 devices, and a legend is provided on the DMXio transmitter bottom label.)

If the DMX/RF Data LED (yellow) blinks several times, then ID0 (zero) is selected.

If the COP/RX/TX LED (green) blinks several times, then ID1 is selected.

If both of the above LEDs blink together, simultaneously, then ID2 is selected.

If those same two LEDs toggle back and forth, then ID3, the RC4 Public ID, is selected.

To ensure any device can always be accessed for reconfiguration, the Public ID3 always enables all RF channels and automatic RF scanning.  Customized RF channel settings are used only with Private IDs (ID0, ID1, and ID2).

RC4 CodeLoader Enable

The RC4 CodeLoader is resident in every RC4 Series 3 device and is carefully protected.  It is enabled by holding the Func/Shift button during power-up.  Then, if CodeLoading does not commence within 5 seconds, the DMXmrx reverts to normal operation.

RC4 firmware files are encrypted before release, and decrypted by the CodeLoader inside the DMXmrx.  The RC4 CodeLoader also guards the device’s unique serial number and RDM address.  (Every RDM device in the world must have its own unique address.)  Updating firmware in your DMXmrx will never corrupt this important device-specific information.

The RC4 CodeLoader facilitates firmware updating without corrupting user settings and configurations, provided the new firmware does not substantially change the list of available settings and their ranges.  In most (but not all) cases, a firmware maintenance release can be installed without effecting DMX channels, curves, and other user or application settings.

Connection to a host PC for CodeLoading is done with an RC4 Series 3 USB CodeLoader Cable.  One end plugs into the DMX miniplug port on the Series 3 device, the other end plugs into a USB port on the PC.

The RC4 CodeLoader application runs natively on Microsoft Windows.  All you need is a working PC, an Internet connection (to download the program and new firmware files), a USB port, and the RC4 CodeLoader Cable.

Dongle Mode

An RC4Magic DMXmrx with firmware version 4.050 or higher can be used as a wireless RF interface for RC4MagicPC software.  This is an alternative to using a dedicated USB Dongle.

An RC4MagicPC dongle is a gateway between RC4MagicPC software and remote RC4Magic dimmers and other devices.


You cannot use RC4MagicPC to configure the dongle device itself.  The dongle allows the software to read and configure settings in other devices wirelessly.  The PC and dongle replace the transmitter in this case.


When operating in dongle mode, the DMXmrx acts only as a PC dongle for RC4MagicPC software, and is entirely controlled by the software.  System IDs programmed in the DMXmrx are not used.  In dongle mode, the DMXmrx can work with any system ID selected with the software.

To put the DMXmrx in Dongle Mode:

  • Power up the DMXmrx and wait for it to complete the start-up sequence
    (ID indication, followed by running as a transmitter or receiver).
  • Press and hold the Func button for severall seconds. When dongle mode is invoked, the LED indicators  will display a unique pattern that is different from normal operation.
  • Connect the DMXmrx to your PC using the RC4 CodeLoader cable. This delivers control data from RC4MagicPC software to the radio circuitry inside the DMXmrx.  All other functions in the DMXmrx are bypassed in this mode.
  • Launch RC4MagicPC software and select the COM port for the CodeLoader cable. Select the System ID to be used. Click any other Tab in the software to commence connection with the DMXmrx Dongle.  These steps are identical for using a dedicated USB Dongle.

The DMXmrx must be in dongle mode and connected with the CodeLoader cable before running RC4MagicPC.  Otherwise, the software will not be able to properly configure the rf circuitry for dongle operation.



Set Defaults

Hold Shift/Func, tap ID, and release Shift/Func  to restore all internal DMXmrx settings to defaults.  Most significantly, this resets the currently selected system ID to ID0.

Manufacturer’s Warranty

The RC4Magic Lifetime Warranty is the best in the business and almost unlimited.  If you have not misused or abused the device, we will fix it for free, forever.  When timing is critical, we can often ship a refurbished replacement unit the same day you contact us, along with materials for returning your old unit. We may ask that you pay the cost of overnight shipping to get it there faster.  Otherwise, we’ll ship regular mail/post at our cost.

Examples of misuse or abuse not covered under warranty include, but are not limited to:

  • Dimmer outputs ganged without ensuring they are configured identically
  • Overvoltage (more than 35VDC applied)
  • AC mains voltage applied
  • Device operated underwater or while saturated with water
  • Device crushed by a car, forklift, sledgehammer, etc.
  • Device set on fire (not as a result of component failure under normal operating conditions)

Very few RC4Magic devices are returned for repair.  Treat your RC4 devices with care and you’re set for life!

RC4Magic Series 3
DMXmrx Device Specifications

  • Dimensions 61mm x 36mm x 20mm
    DMX Connection:  5mm miniplug (non-standard)
  • Power Input: 6VDC – 35VDC, 0.4W idle draw, ~87% regulation efficiency, screw terminal connections
  • 3 user-selectable RC4 Private System IDs, plus the RC4Magic Public ID
    (each ID supports one independent DMX universe)
  • Any number of DMXmrx receivers may be used in a system.
  • DMX Output: meets USITT DMX512/1990.
  • The DMX specification allows up to 32 devices on a DMX output.  The DMXmrx data output exceeds this requirement and is capable of driving additional devices.
  • Internally protected against static discharge and excessive line loading.



RC4Magic DMX Protocol Compliance

  • DMX inputs and outputs comply with USITT DMX512/1990(4us).
  • Packets with non-zero start codes are not transmitted.
    RC4Magic cannot transfer proprietary data or RDM packets.
  • DMXmrf receiver output replicates DMXio transmitter input, providing the same number of DMX channels and the same number of packets per second (pps).
  • Minimum number of DMX channels per packet: 1
  • Maximum number of DMX channels per packet: 512
  • Maximum packet-per-second rate:
    1 pps with 512 DMX channels, 10000ps with 1 DMX channel

RC4Magic RF Specifications

  • Indoor/Urban Range: 250’ typical
  • Outdoor Line-of-Sight Range: 300+ feet typical
  • Transmit Power Output: Up to 63 mW (18 dBm) EIRP 1
  • Receiver Sensitivity: -100 dBm
  • Operating Frequency: 4GHz ISM band,
    DSSS (Direct Sequence Spread Spectrum)


1 Lower RF power levels are required for compliance in some jurisdictions.

RF Agency Approvals:

United States


The RC4Magic DMXmrf complies with Part 15 of the FCC Rules. Operation is subject to the following two conditions: (i.) this device may not cause harmful interference and (ii.) this device must accept any interference received, including interference that may cause undesired operation.


The RC4Magic System, and the DMXmrx in particular, are CE compliant.

A Declaration of Conformity has been issued for the Radio Frequency Transceiver Module used in RC4Magic 2.4GHz devices, concerning emissions, EMC and safety. Files can be obtained by contacting RC4 Wireless.

When operating in Europe, RC4Magic transmitters must be operated at the lower RF power output level, which is 10dBm.  Additionally, European regulations stipulate an EIRP power maximum of 12.86 dBm (19 mW) when integrating antennas with the DMXio-HG.

In France: Outdoor use limited to 10 mW EIRP within the band 2454-2483.5 MHz.

In Norway: Norway prohibits operation near Ny-Alesund in Svalbard. More information can be found at the Norway Posts and Telecommunications site (


Rc4Magic 2.4GHz devices contains Model XBee-PRO Radio, IC: 4214A-XBEEPRO


ID: 005NYCA0378

Other Jurisdictions

Contact RC4 Wireless for additional information.




How to Reach RC4 Wireless
Physical Address


RC4 Wireless is a registered trade-name of Soundsculpture Incorporated of North Carolina.


Soundsculpture Incorporated / RC4 Wireless

13604 Heathwood Court

Raleigh, NC, 27615


Telephone / Fax

Toll Free 1-866-258-4577 (North America)

North Carolina, USA, Local 919-229-9950

London, UK +44 (0)20 3289 8765

Emergency Cellular 919-400-3961

Toll Free Fax 1-866-237-6641 (North America)



Skype rc4acw



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RC4Magic Series 3 DMXmrx Wireless DMX Transceiver

User Manual v1.0 Feb 2016

© 2016 Soundsculpture Incorporated / RC4 Wireless

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