Protocol: RDM (configuration via DMX)

[DynamoBen]

DMX is a single direction protocol for setting dimmer levels. RDM however is a bidirectional protocol that allows communication with remote DMX devices. RDM is able to set properties like starting address from a remote location; you never need to set dip switches.

Nice summary with resources:
http://www.rdmprotocol.org

This document gives a pretty good description of what RDM is:
http://www.artisticlicence.com/WebSi...appnote005.pdf

The standard can be purchased from ESTA.
RDM E1.20

[DynamoBen]

RDM Enable the Open DMX USB

After chatting with Henne here:
http://www.doityourselfchristmas.com...ead.php?t=3479

We discovered that with a minor modification the Open DMX USB can communicate with RDM enabled DMX devices. This opens up a world of possibilities for us. Like remote start address setting, Firmware Updates via DMX, and remote device status. See the sticky titled “RDM” for a more in-depth explanation of what’s possible.

What you will need:

X-acto Knife
Mod Wire
Fine tip Soldering Iron
Enttec OpenDMX USB schematic

NOTE: This will void your warranty, and could damage your device if not done properly. Perform this mod at your own risk.

To enable RDM you will need to cut a trace between the SP485CN and FT232BM (RTS). Once cut a jumper wire will need to be soldered between the SP485CN and FT232BM (TXDEN). Take a look at the schematic and device prior to starting this mod to be sure you understand what this mod entails.

Steps:

1. Locate the FT232BM and SP485.
2. Find the trace between the FT232BM pin 23 (RTS) and SP485CN pins 2 & 3 (RE & DE).
3. Cut the trace between these two ICs and verify there is no longer continuity.
4. Find pin 16 on the FT232BM (TXDEN).
5. Solder a mod wire between the FT232BN pin 16 and the SP485 pins 2 & 3.

Testing:

Launch Vixen, or the Enttec test app, and ensure DMX-out is working. If you have another DMX transmitting device now is a good time to test DMX-in using the Enttec app.

Next go here and download the Open RDM software:
http://www.hoelscher-hi.de/hendrik/english/openrdm.htm

Connect the OpenDMX USB to a RDM enabled DMX device and try to manipulate the devices parameters via OpenRDM. It works!!!

Happy RDMing.