LED PAR Mysteries

[timsabre]

the master adds 6 to the DMX data for any subsequent units, ie DMX 001 data from the desk is changed by the master PAR unit to DMX 007.

What fixtures are those? That's really unusual...

 

[alistermorton]

That's a PAR can doing DMX rewriting? Maybe it does, I guess..

 

Really, I've seen it myself, having any device on the chain anywhere which isn't set to full DMX control only (i.e. instead is set to manufacturers mater/slave magic sauce) will cause problems. Mater/slave is intended for disco Dave to just plug his cans in and let them do their thing. You have a desk, so configuring the fixtures properly is really the only way to go. If they're borrowed units, take a photo of the settings before you change them, change them on the ground and make sure it all works first, not up a ladder, then you can put them back afterwards.

 

BTDTGTTS.

[timsabre]

It is technically possible if the LED par can does RS422 rather than RS485. Very unusual though. It would also mean the par can would break the DMX chain if unplugged from power.

[DrV]

It is technically possible if the LED par can does RS422 rather than RS485. Very unusual though. It would also mean the par can would break the DMX chain if unplugged from power.

Not necessarily - I know of at least one fixture which has a relay between DMX in and DMX out which connects data through when de-energized but separates in and out when energized. (and terminates the incoming DMX line)

Dave.

[sunray]

These fixtures do break the DMX if not powered which is another reason I now run them from a splitter, I have some RGB LED decoders: https://www.ebay.co.uk/itm/DMX512-Controller-DMX3-Channel-Decoder-Lamp-With-RGB-Controller-Sub-Controller/391828755525?_trkparms=aid%3D555017%26algo%3DPL.CASSINI%26ao%3D1%26asc%3D55148%26meid%3Dc392a06175c748d3afcd6a5027bc7393%26pid%3D100505%26rk%3D1%26rkt%3D1%26%26itm%3D391828755525&_trksid=p2045573.c100505.m3226 which have buffered DMX and I found out during a show that there is no failsafe when someone decided their phone was more important than lighting, and I have some other RGB LED decoders: https://www.ebay.co.uk/itm/DMX512-Decoder-Board-Codering-Module-Controller-3-Channel-For-Stage-Light-PL/183574778906?hash=item2abde8d41a:g:q1AAAOSw19dcC9I8:rk:1:pf:0 with fixed 001,002&003 addresses that subtract 3 from the outgoing DMX data so units can be stacked without doing any addressing.

[bigclive]

Talking of people charging phones.... At the Edinburgh Tattoo this year one of our techs caught a tourist unplugging a Ceeform on the truss in the drawbridge area and trying to jam their two pin charger into it.

 

It's glorious. It's just like all the dark sci-fi films predicted. People will steal power from anywhere to try and remain connected to "the net".

[sunray]

Talking of people charging phones....  At the Edinburgh Tattoo this year one of our techs caught a tourist unplugging a Ceeform on the truss in the drawbridge area and trying to jam their two pin charger into it.It's glorious.  It's just like all the dark sci-fi films predicted.  People will steal power from anywhere to try and remain connected to 'the net'.

I've lost count of the number of times it's happened to me over the years and since long before mobile phones were even thought of, I'd say number one guilty party is the bouncy castle followed by the kettle.

 

And talking of bouncy castles, they are also number one for tripping RCD's and without exception refuse to accept they have a fault.

 

On another occasion I had a run of CEEforms to stalls at a fete and the RCD tripped twice, on the second I inspected and found a campervan on the adjacent field had tapped in so while power was off I removed his splitter and two extension leads and left them laying in the hedgerow. As they were still there at the end of the following day when I packed up...