To order any of these products please go to the Order page.

Always feel free to call/e-mail us with support questions!

Contact information is at the bottom of the page or e-mail by clicking the button above.

Reduction of Hazardous Substances (RoHS)

We are in the process of converting all of our manufacturing over to RoHS compliant.

The RoHS status of every product is noted on the Products page.

Statement on RoHS, Lead-Free, and Proposition 65 Compliance

Lighting Products

If you'd like to learn more about the DMX Protocol and uses for it, a very good web site is DMX512-Online run by Ujjal Kar. There is also an official FAQ at USITT. The complete specification for DMX512-A is contained in the ANSI E1.11-2008 standard which is available from the ANSI Web Store.

4201-B, stellarDMX DMX Controller and MIDI adapter

The 4201-B may be used in many different ways; we will assist you in getting your system set up and working. We’ll even write simple macro files for you if needed and ship units with macros, settings already loaded.

USB connections to Mac OS X and Linux systems now work with no adapters. We recommend USB connections whenever possible.

MIDI connections require our MIDI to RS-232 adapter which plugs into and is powered by the 4201-B. The MIDI adapter requires version 2.10 or later firmware in the 4201-B, other than that there is no special software needed.

The Model 4201-B may be controlled directly from any application or programming language on any machine that can talk to an RS-232 or MIDI port. The USB interface lets a Windows, OS-X, or Linux computer see the 4201-B as a normal RS-232 port, so no software changes are needed to use either the RS-232 port or the USB port on those systems.

The 4201-B allows setting a slower frame rate for use with low cost dimmers, if you have flickering problems try setting the frame rate to 20 (hex) using the “N” command.

MIDI capable Firmware, version 2.19 See the manual for the version you currently have for firmware update instructions.

New in this version, ^P adds soft patching for all 512 channels (works with or without stellarConsole). Also the ^D and ^F commands have changed slightly.

Also includes MIDI functions including fading to presets using the fade time stored by stellarConsole. Now you can set up your show with stellarConsole, copy it over to the 4201-B, and then run it with your MIDI sequencer. New macro command has been added to make it easier to step through presets and use all 8 User inputs with switches.

4201-B Instruction Manual, version 2.19

Manuals for older versions

All files included on 4201-B CD including previous firmware versions.


stellarConsole, Version 1.7.5, a 24 channel control program for Windows, OS X, Linux. Recently added features are soft patching, naming faders, and moving faders in groups. This will also save your cues and fade times to non-volatile presets in the 4201-B for later access by a macro or MIDI command.

The above program is courtesy of ChromaKinetics.

For Mac and Windows users who don't have a serial terminal program, Cool Term by Roger Meier works and is free. The only problem we've seen with this is in Windows if the serial port has been opened by another program such as HyperTerm, the computer will have to be rebooted before CoolTerm will open the port. Version below is 1.4.3.

CoolTerm for Windows

CoolTerm for Mac

CoolTerm for Linux

For Linux systems you may also use GtkTerm.

Some of our products use the FreeRTOS operating system. The source code is licensed by the *modified* GNU General Public License (GPL). The source code and license file are provided here:

Handy utilities to convert MIDI files to/from text files. Allows creating/editing MIDI files with a text editor. Windows only, source files included. MIDI-MTX

Application notes

Decimal to Hex conversion Table

Percent to Hex conversion Table

Using sliders (potentiometers) with the 4201-B

Lighting a sculpture without a computer

Museum/kiosk display without a compute

Interfacing to computerized architectural lighting systems

DMX512 Controlled 4-Channel DC Dimmer

Our DC Dimmer has been upgraded to Version 2 which now features Isolated and Protected DMX input, 8 and 16 bit dimming, and many special order options including ModBus control, dedicated stepping motor version, and pre-programmed lighting sequences.

Version 2 Dimmer Instruction Manual

DMX Stepping Motor Video (10 MB) of a stepping motor being controlled over DMX512 using our standard DC Dimmer.

The following manual is for the original version only.

Original Version Dimmer Instruction Manual

Switch-4 and Switch-4X

The Switch-4 allows simple control of many devices that prior to this required expensive, complicated controls. One to four inputs (can be buttons, switches, relays, sensors, logic level outputs, etc.) are constantly monitored and every time one of the inputs changes it sends a command to whatever it's connected to. There are currently two versions, MIDI and RS-232 with both standard and customized commands.

The MIDI standard version sends out simple Note On and Note Off commands. For example when Switch #1 closes it will send out “Note 1 On”. When Switch #2 opens it will send out “Note 2 Off”.

The RS-232 standard version sends out a single letter followed by a carriage return. For example, when Switch #1 closes it sends out a capitol A. When Switch #2 opens it will send out a lower case B. Upper case = Switch closed, lower case = Switch opened.

The Switch-4X version allows you to change the output data, RS-232/MIDI mode, output polarity, debounce time, and baud rate whenever you wish. It requires use of either the FTDI cable that we sell or you may make your own. You will also need to use our free setup utility, currently this utility requires Open Office software which is free and runs on Windows, OS X, and Linux systems. The setup utility is open source so you may modify it to suit your needs.

Switch-4 Manual for MIDI and RS-232 Standard Versions

Switch-4X Manual for Extended Version (includes Setup Utility instructions)

Switch-4X Setup Utility, Setup Software License Agreement (GNU GPLv3)

CoolTerm for Windows

CoolTerm for Mac

CoolTerm for Linux

For Linux systems you can also use GtkTerm.


This is currently offered in an RS-232 version with future customized versions available on special order. For many applications, power relays (solid state or mechanical) will be used to drive the final load (neon transformers, incandescent lights, motors, etc.) but there is no problem directly connecting LEDs, small incandescent lights and motors as long as they operate on 9-24V DC and draw ¼ Amp or less.

We offer customized systems including mounting this board, power supply, and relays in an enclosure at reasonable prices. Contact us for details.

We can also write a Sequencer program to meet your needs and ship the product ready to connect and use. For simple programs there is no charge for this. For complex programs there will be a reasonable fee.

We offer programming support via telephone and e-mail at no charge.

User Manual for firmware version 20131014

Firmware version 20131121

Old Support Files (manuals, firmware)

Firmware updates are optional, only install if you need the updated features.

You will need a terminal emulator program to set up the Sequencer, you may use any of your choice. If you have us load the program in for you, then you will only need the terminal emulator if you wish to make future changes.

The following terminal emulators are offered free.

CoolTerm for Windows

CoolTerm for Mac

CoolTerm for Linux

For Linux systems you can also use GtkTerm.


An example of a typical application program would be a museum display that has a push button to start a sequence of operations. In this example we have the following items connected:

Channel 1: Idle lighting (static lights when inactive)

Channel 2: Audio PLAY trigger

Channel 3: Light 1

Channel 4: Light 2

Channel 5: Motor

CTS: User START button

Programming explained in detail in the User Manual, but for a quick example the program would have the first line turn the Idle lighting on while turning everything else off. It would look like this:

* 1 S 0b00000001 1

The next line would simply hang out waiting for the push button:

* 2 J 2 0x11

After that we would have lines that step through turning on the Audio PLAY output and the lights/motor at appropriate times. Each item would be a single program line similar to the first line above. After the last item was done there would be a Jump back to the very first step to go back to the idle state and wait for the button again.

4200, 4201, 4201a

These models have been replaced with the 4201-B. The 4201-B supports most of the functions of the 4200, 4201, and 4201a products but not all. Most importantly, the SmartLight™ Theater Lighting Software from Edgeview Software LLC does not currently support the “B” version, it has been discontinued. The free stellarConsole program above is the new replacement for it.

Support files for the superseded Model 4201a

Support files for the superseded Model 4200

Durand Interstellar, Inc.
219 Oak Wood Way Los Gatos, California 95032-2523 USA
Ph: +1 408 356-3886
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