DMXio / DMXio-HG Transceiver User Manual

Wireless DMX

A pair of RC4Magic Series 3 DMXio units replaces a DMX data cable in lighting control applications.  Configure one device as a transmitter, and one or more devices as receivers.

Any number of DMXio 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 DMXio is easily configured as a transmitter or receiver with the push of a button, and remembers this and other settings on every power-up.

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.

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

The DMXio provides male and female 5-pin XLR connectors, compliant with USITT DMX512/1990.  Internally, these two connectors are directly wired together with no active electronics in the signal path.  They can be used for data pass-through and will not fail in the event of DMXio power failure.

DMX Termination

A DMX terminator is built into the DMXio and can be toggled on/off by pressing one button.  The state of termination (on or off) is remembered and will be restored when power is cycled.

DMXio Auto Mode

As of firmware version 4.050, the default mode for the DMXio is Auto mode.
This mode uses the connection context of the device to automatically select Transmit or Receive mode.  More information is provided in the button functions section.

DMXio Transmit Mode

As a transmitter, the DMXio decodes the DMX universe arriving at the DMX connector, encodes and encrypts it, and broadcasts it using Direct Sequence Spread Spectrum (DSSS) digital radio. Unlike wired DMX, the RC4 wireless signal includes error checking and correction codes, and is not affected by minor interruptions and interference.

Channel Range Limiting

By default, the DMXio transmits the entire DMX universe connected to the wired DMX data input.  The universe can be any number of channels from one to 512.  The maximum number of channels in a DMX universe is 512, but some controllers produce fewer (64, 128, or 256 channel consoles are common).

To reduce wireless bandwidth consumption, it is sometimes desirable to limit the number of DMX channels actually being transmitted.  For example, if you are using RC4Magic to wirelessly control two DMX4dim wireless dimmers, with a separate DMX channel assigned to each dimmer, you only need to transmit data for eight channels.  If they are contiguous channels (say, 400 – 407), then limiting the transmitter to just that range reduces the required wireless bandwidth by as much as 99.98%!

If you’re not sure how many channels you are using, or if you are using DMXio units for full-universe cable replacement, stay with the default settings and transmit the entire universe.


An LED indicates when channel range limiting is active.  If some channels are not arriving at an RC4Magic receiver, check this setting.


DMXio Receive Mode

As a receiver, the DMXio decodes the wireless signal from the transmitter, rebuilds the DMX universe, and regenerates a standard DMX signal with the same number of channels and the same packet rate as the data going into the transmitter. DMX in and out are compliant with USITT DMX512/1990.

When Channel Range Limiting is used at the transmitter, channels that are not being sent are output by the receiver with a value of zero.

Power Requirements

Power can come from the supplied wall transformer, from external batteries, or, when optionally enabled using internal jumpers, from XLR pins 4 and 5. A pack of five (or more) AA or AAA batteries, or even a small 9V battery, can be used for portable operation with, for example, a Goddard Design DMXter, a BCI Pocket Console DMX, a Fleenor Gizmo, or any other DMX signal source.  The input voltage range is 6V – 35VDC, and the RC4Magic DMXio consumes approximately 0.6W of power when transmitting with maximum RF power (63mW).

Signal Range and Antenna Options

In many cases, the DMXio can be connected right at your lighting console or other controller, before your DMX signal continues to other devices in your system. The distance from console to indoor stage is rarely more than 100 feet, well within the 300 foot range of RC4Magic.

When operating outdoors, place the transmitter (or the transmitter antenna) above people’s heads and above other obstructions for reliable range exceeding 300 feet.  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.

The standard model RC4Magic DMXio uses an internal omnidirectional antenna.  The DMXio-HG provides an RP-SMA antenna connector and is sold with a simple omnidirectional 3 dBi “rubber duck” antenna.

For longest possible range, use high-gain and/or directional 50-ohm antennas designed for the 2.4GHz band.

Restore Defaults

If user settings for System ID, DMX termination, or channel limiting 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 ID3/Public button, and release the Func button.  The device will restart, which may take up to 6 seconds.

Further details about this and other functions are described later in this manual, in the section Func/Shift Two-Button Functions.

DMXio User Interface

The DMXio user interface consists of six LED indicators and five recessed buttons.  The LEDs are behind small round holes; the buttons are behind small slotted openings.  DMXio settings rarely need to be changed, and keeping the buttons recessed ensures settings will not be accidentally changed while handling the device.  It also reduces the likelihood of tampering.

Buttons should be operated by inserting a small tool – like a bent paperclip – into the slotted openings.

Do not insert anything into the round LED holes.  Doing so could damage the device and may not be covered by the RC4Magic Warranty.

Selecting an RC4Magic System ID is done by holding a button while powering up a unit.  These are “power-up” or “hidden” functions.

The most commonly used features and functions are accessed by pressing one button while the unit is powered on and operating.  For example, the RX/TX/Auto button toggles between receive, transmit, and automatic selection of receive or transmit mode.

A few additional features are accessed using the Func/Shift button: hold this button then tap another button.


The label on the bottom of the DMXio provides a legend for the LEDs and buttons.  All settings (except Dongle Mode) are saved in non-volatile memory and are restored on each subsequent power-up.


LED Indicators

With the DMXio mounting flanges down and the connectors facing you, the LEDs left-to-right are:

DMX/RF Data – Yellow

In transmitter mode, this indicator is on when valid DMX data is present at the wired DMX data connector.  If DMX data is discontinued, this indicator will remain on for the data time-out period, usually 1 second.  This is because the DMX specification allows data packets to be spaced up to 1 second apart.

In receiver mode, 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/RX/TX – Green

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

When the COP indicator is blinking with a 50% duty cycle (equal time on and off) then it is in Auto mode and will automatically select either Receive or Transmit mode as appropriate.  (More information is provided in the button functions section.)

When the COP indicator is primarily on (illuminated) then the DMXio is in transmitter mode.  The COP feature causes it to blink off briefly but regularly.

When the COP indicator is primarily off (dark) then the DMXio is in receiver mode.  The COP feature causes it to blink on briefly but regularly.

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 Power/RSSI – Red

In transmitter mode, this LED indicates the RF power level being used for transmission.  It blinks faster with higher power levels.  Note that the highest levels are not permitted in some jurisdictions.

In receiver mode, this LED is a receive signal strength indicator (RSSI).  Faster blinking indicates a stronger more robust signal.

Early firmware versions do not yet have the receiver RSSI display feature implemented.
CodeLoader updates will provide this when available.

DMX Channel Range Limit – Yellow

If the range of transmit channels has been reduced (Transmit Low Channel is higher than 1, or Transmit High Channel is lower than 512) then this indicator is on.  This is a warning that not all channels are being transmitted. Channels that are not transmitted will have a level of zero at the receiver output.

If this LED is on or blinking, and some DMX channels are not working over your wireless link, Channel Range Limit is most likely the problem.

DMX Termination – Green

If DMX termination is enabled, this indicator is on and an internal terminator is applied to the XLR connections.

RF Connect – Blue

In transmitter mode:  After a brief initialization, this indicator will blink steadily to indicate active transmitter mode.

In receiver mode:  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 as a connected and active wireless DMX receiver.

Selected ID Indication

On power-up, the DMXio indicates which RC4Magic System ID is selected with a series of blinks on the two left-most LEDs.  A blink-pattern legend is provided on the bottom device 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).

Power-Up Button Functions

If a button is held down during DMXio 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 DMXio 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.

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 DMXio reverts to normal operation.

RC4 firmware files are encrypted before release, and decrypted by the CodeLoader inside the DMXio.  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 DMXio 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.

Single-Button Functions

The most commonly used DMXio functions are accessed with a single press of a single button.  All settings (except Dongle Mode) are saved in non-volatile memory and restored on subsequent power-ups.

RX/TX/Auto (Receive/Transmit Mode)

As of firmware version 4.050 (released in October 2015), the DMXio is by default in Auto mode, which automatically selects transmit or receive mode depending on the context of operation:

  • If RC4Magic wireless DMX traffic is detected on the currently selected system ID, the DMXio will operate in Receive mode.
  • If wired DMX data from a console or other DMX controller is detected at any 5-pin XLR connector, the DMXio will operate in Transmit mode.
  • If neither are present, it will continue monitoring until one of the above conditions occurs.

For most users there is no reason to not leave the DMXio in Auto mode.  Some operators may prefer to force either transmit or receive mode.  Press the RX/TX/Auto button to rotate through receive, transmit, and Automode, restarting the DMXio in each new mode.  The blink pattern of the COP LED indicates the current mode.

TX Low Channel

This feature uses RC4 OneTouchTM – the same process used to assign channels and curves on RC4 wireless dimmers.  You need a DMX controller capable of clearing all DMX channels to numeric zero and bringing up a single channel to a level above 20%.

To set the TX Low Channel:

  1. Connect a DMX console or other controller.
  2. Clear all DMX channels to zero. Beware of fixture profiles that clear, for example, moving-light pan/tilt channels to a central level, rather than true zero.  All DMX channels must be at actual zero.
  3. Bring up the lowest DMX channel you want to transmit wirelessly. Set it to any level that is higher than 20%.  It should be the only non-zero DMX channel.
  4. Press and release the TX Low Channel button.

That’s it!  If you have selected a channel that is higher than 1, or if the TX High Channel is already set to a value lower than 512, the DMX Channel Range Limit LED will be on.

You can disable this feature by either setting TX Low Channel to 1 using the process above, or using the Restore Defaults function.

TX High Channel

To set the TX High Channel:

  1. Connect a DMX console or other controller.
  2. Clear all DMX channels to zero. Bring up the highest DMX channel you want to transmit wirelessly.  Set it to any level that is higher than 20%.  It should be the only non-zero channel.
  3. Press and release the TX High Channel button.

That’s it!  If you have selected a channel that is lower than 512, or if the TX Low Channel is already set to a value higher than 1, the DMX Channel Range Limit LED will be on.

You can disable this feature by either setting TX High Channel to 512 using the process above, or using the Restore Defaults function.

Dongle Mode

An RC4Magic DMXio 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 DMXio acts only as a PC dongle for RC4MagicPC software, and is entirely controlled by the software.  It does not matter if the DMXio is normally in transmit or receive mode, and system IDs programmed in the DMXio are not used.  In dongle mode, the DMXio can work with any system ID selected with the software.

To put the DMXio in Dongle Mode:

  • Power up the DMXio and wait for it to complete the start-up sequence
    (ID indication, followed by running as a transmitter or receiver).
  • Press the Dongle Mode button. The LEDs on the DMXio will begin chasing left-to-right, indicating that Dongle Mode is active and ready to send data wirelessly.  Occasionally these LEDs will chase right-to-left to indicate that data has been received wirelessly.
  • Connect the DMXio to your PC using the RC4 CodeLoader cable. This delivers control data from RC4MagicPC software to the radio circuitry inside the DMXio.  All other functions in the DMXio 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 DMXio Dongle.  These steps are identical for using a dedicated USB Dongle.

The DMXio 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.



Func/Shift Two-Button Functions

Lesser used DMXio features and functions are accessed by pressing and holding the Func/Shift button and then briefly pressing (or tapping) one other button.

RF Power

Hold Shift/Func and tap the ID0 button to increment to the next RF power level.  If the level is at maximum, it rolls over to the minimum on the next button press.  Higher power levels are indicated by faster blinking of the RF Power LED.

DMX Termination

Hold Shift/Func and press the ID1 button to toggle DMX termination on/off.  The current state is indicated by the DMX Termination LED.  When the LED is on, termination is active.

Set Defaults

Hold Shift/Func, tap ID3 (the button immediately beside Shift/Func), and release Shift/Func to restore all internal DMXio settings to defaults.  This includes:

  • Select ID0 (zero)
  • TX Low Channel is 1
  • TX High Channel is 512
  • DMX termination is off
  • RF power is at maximum (100mW)

Was this article helpful?

Related Articles