all dimmer chanels are flickering as soon as FLX-S48 desk is connected.

[Claude Schockmel]

Hi everybody,

 

It's a while I've not been here. I have a problem by connecting the FLX-S48 desk in an older 48ch static dimmer installation.

The dimmers are 8x IES 6x2.3KW digital dimmers.

Tomorrow, I'll try to put a temporary DMX cable, so that I can see and eliminate all possible trubbles. In the meantime, I'll connect some singel dimmers and some LED-fixtures, to investigate what should be the reason. Today, I've mesured the impedance of the long DMX cable approx 50m long. Pin 2 40.5 Ohm, Pin 3 26.6 Ohm, so could be the first problem.

 

Have anybody seen that kind of problem by changing FLX-S48 desk in older dimmer installation?

 

Many thanks' in advance and have a nice evening.

 

Claude Schockmel

L-1714 Luxembourg.

 

[KWR88]

Hi Claude,

 

Check that rig sync is also turned off as well as it could be the dimmer does no like the RDM signal.

[kgallen]

That seems quite a high resistance for a cable. Also that the differential pair on pins 2 and 3 have very different resistances looks very suspicious. A thorough check of the cable and connectors/termination is needed. 

[iank99]

12 hours ago, kgallen said:

That seems quite a high resistance for a cable. Also that the differential pair on pins 2 and 3 have very different resistances looks very suspicious. A thorough check of the cable and connectors/termination is needed. 

Indeed - for a 50m cable run, I'd expect an almost zero reading for impedance from experience. It sounds like a solder joint has gone bad or there's a cable  break near the connectors causing intermittent high readings.

[DALX]

It is more reliable to run non RDM fixtures from the XLR3 socket on the FLXS48 if you are only using one universe as the DMX receive timing of some equipment cannot handle RDM. Jon Hole  mentioned in a post on 24 November 2017 
 

Quote

FLX S has two outputs - a 3pin and a 5pin. If you have a 1 Universe FLX S, by default both ports will output the same DMX data, but the 5pin will include RDM and the 3pin won't include RDM. This behavior can be changed in SETUP > Inputs & Outputs.

Another useful trick is addressing the fixture into the higher numbers. Usually above address 32 helps, but if not above address 257 should definitely help.

 

[Claude Schockmel]

Hi all,

 

Thanks' for response and propositions. Yesterday morning, I solved my problem very quick and easy, it was RDM, to be disabled.

 

Everything is running perfect. The resistance was measured from pin 2 to 1 and from pin 3 to 1. Should be OK at a distance of 50m.

 

Cheers

 

Claude