MADRIX Forum • Plexus Output strange
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Plexus Output strange

Posted: Tue Jun 23, 2020 9:46 pm
by schaf82
Dear Madrix Team,

We have a plexus running on the other side of the world (Korea) and only team viewer connection, so our means of investigating the problem are limited.

Our setup:
We have a plexus connected to a PC running MADRIX via USB running 527 lights on two Universes.
Universe 1 goes directly to the DMX Controller controlling a set of LEDs. Universe 2 is connected to a "DECA Box" listening to 8 channels and the rest of the channels going through the box to DMX Controller triggering light effects ( ... mx-bridge/) . This box converts DMX to MIDI. We use it to control sound based upon the light movement we control via a script.

This setup was working perfectly fine for about 4 weeks (been switched on / off) every day. All of a sudden we have problems:

1. signals coming from the "DecaBox" are all over the range from 0-255 DMX / 0-127 MIDI also the DMX Watcher is showing only values of either 1 (which converts to C-2 off in MIDI) or values in the range of 120-137 (120 would convert to C2 off in MIDI ) but we get super strange values all over the MIDI range.

2. Lights started to randomly "blink".

3. Parts of the installation are completely dark.

What have we tested so fare:

a. We removed the "DecaBox"from the equation. this resulted in no changes to problem 2/3
b. We have removed all scenes from the Plexus just in case.


c. Is it possible that the Plexus or anything else is introducing some kind of noise to the DMX Signal?
d. Both DMX and MIDI are digital? so conversion should be also digital?
e. Could it be that USB2's bandwith is to small ?
f. Windows updates are on (unfortunatly it is a coperate pc), are there any reported issues with windows 10 and Plexus / USB?
g. Any further things you suggest that we can test?
h. Any reported problems with power in South Korea?

Any help would be really really appreciate

Best Richard

Re: Plexus Output strange

Posted: Fri Jun 26, 2020 3:59 pm
by Guertler
Hello schaf82,
Welcome to the MADRIX forum.

The PLEXUS it self will not create any noise at the DMX output. It is always send a DMX signal according to the DMX specifications.
Interferences on a DMX line can generate such strange effects. Such interferences may come of if a connected fixture is not working 100% according to the DMX specication especially in processing the received Data + and Data - signal or if a fixtures is sending to much power over the DMX bus. Furthermore faulty DMX cables are also influencing the signal. I would recommend to check the DMX cables first.

It is no problem to control the 2 DMX universes via USB. But please double check the energy settings of the used PC. "USB selective suspend setting" sould be disabled.

Please double chek the MADRIX setup. Are all created effects are still ok or has somebody changed something?

Re: Plexus Output strange

Posted: Mon Aug 15, 2022 4:10 pm
by Guertler
Hello AllanPeter,

Can you please explain a bit more where you need help?