Logic RDM Sniffer
- A Logic or Logic 16, but see the note below.
- 485 driver circuit
- XLR connectors.
You need some hardware to convert from the differential 485 levels to a signal which the logic can understand.
At the basic level you only need an RS-485 receiver like the Maxim MAX485 or Linear Technology LT1785 to translate from the DMX/RDM differential levels to a TTL level that the Saleae Logic Understands. File:Example.jpg
Saleae provides the Logic App which works on Windows, Mac and Linux. The application has a plugin to decode DMX, but it doesn't understand RDM data. The tool is best for analyzing the signal timing rather than the high level messages.
OLA has a text-based DMX/RDM sniffer that works with the Logic (it could easily be extended to work with the Logic 16). It can be found in tools/logic directory of the OLA sources.
- the sniffer doesn't understand DUB responses yet since it looks for breaks.
- it may struggle with signal timings that are at the edge of the E1.11 standard. If you experience problems with the sniffer please email the Open Lighting Mailing List