+ve AND -ve Demux

[richard]

But, looking at the original message I think that the dimmers he wants a demux for are not the betapacks..

[peternewman]

Hi all,

 

Thanks for all the replies.

 

The Betapacks with DMX do not need to be demuxed, however we sometimes have some drama betapacks which do need to be demuxed, these can indeed be switched.

 

Thanks for the info MarcT I shall look into the dimmer curve issue. I thought from the PDF that there would be a set of dip switches by each 25way D output but it sounds as if this is not the case. Also being really pedantic the output is 25way D plug, whereas the dimmers connect with a 8way DIN plug. Also some of our dimmers do have bleecon, but from what we found before the z88's would fit but would not lock, which shouldn't be a problem.

 

Does anyone know if the Stand/Botex dimming curves would match okay with ones setup on the betapacks. Also where is a source of cheap bleecon or locking din leads, as we are proposing to have a row of sockets and then use short leads to connect from the 25way D breakout to the dimmers.

 

Rather ridiculously we could in fact buy 2 Strand/Botex demuxes and make up all the leads for less than the price of a Z88 demux!!!

 

Hence allowing us to put all the dimmers consecutively without softpatching by arranging the demux channels to overlap.

 

 

Thanks

 

PN

 

PS Please can DMX be added to the dictionary!

[robloxley]

Well you can buy 8 core control cable and DIN connectors from RS, VDC, Canford and the like.

[sguy42]

The Zero88 betapacks will accept either a 0v to 10v or a 0v to -10v input. You need to swop a jumper around on the control board. Then you only need the demux to output one set of voltages.

 

Very good point that we all managed to miss! The Betapack II's have it switchable on the front panel IIRC.

If your using a DEMUX you don't need to swap the jumper over. This controls the low voltage supply for running a small desk. The dimmers themselves are autosensing.

 

However you do need to make sure that you don't connect the power supply pin to anything else, particularly the supply from another dimmer of opposite polarity. My method (which isn't completely idiot proof) has been to fit the (optional) Bleecon connector for use with -ve systems but only wire 7 pins (six channels and 0V).

 

shane

[Tomo]

[snip]

Also where is a source of cheap bleecon or locking din leads, as we are proposing to have a row of sockets and then use short leads to connect from the 25way D breakout to the dimmers.

[snip]

Farnell is probably your best bet for cheap connectors and cables. Very large stock, and much cheaper than RS.

Only problem with them is they often want you to buy five or ten units, rather than one.

 

However their keyword search is pretty terrible, although it is better than it used to be!

I find that the best way to find equipment to do a specfic job is to find some in the RS catalogue and then search the Farnell catalogue by manufacturer's code.

[Andrew C]

Indulging in a bit of thread-necromancy here, but can anyone tell me how the 25D connectors are pinned out for the Botex? My guess would be 1-24 are channels, with 25 as a common. We're ordering some of them soon, but I'd like to get the leads made up in advance.

[boatman]

Indulging in a bit of thread-necromancy here, but can anyone tell me how the 25D connectors are pinned out for the Botex? My guess would be 1-24 are channels, with 25 as a common. We're ordering some of them soon, but I'd like to get the leads made up in advance.

 

No user manuals can be found on their website, but there's always a chance that an email to info@botex.com might produce an answer.

[johnhuson]

Strand used to sell a re-badged version of the Botex units, the manual can be found HERE.

[J Pearce]

IIRC its not 1-24 as channels and 25 as common (which is Sirius pin-out I think), I'm sure it was more complex when we soldered one up for the Students Union at Derby.

It may be 1 as common then 2-25 as channels.

[Andrew C]

As I thought; 1-24 and common on 25. TVM John.

[peternewman]

We never got the demux in the end and I think most of the old negative racks got skipped. Anyway ISTR there being some discussion and confusion somehow regarding these Andrew, it may have just been with ready made breakouts, but I'm fairly certain some people encountered some weird pin-out issues. The Strand and Botex were definitely identical weren't they?

[Don Allen]

These demux's are also badged as a Showtec Multi-Exchanger Manual, and most manuals do not give the sex of the 25 pin D connectors. There are two numbering methods, one follows the D connector numbering as the Strand does, odd numbers on top, even numbers on bottom, the other has 1 to 12 on the top row and 13 to 24 on the bottom row, (Theatrelight from memory). 25 is common for both.

 

Some use female D connectors, (Showtec), some use male, so you may end up with a mirror image of what you want for your leads so use a sex changer to convert their pinout.

[dbuckley]

I have a multi-exchanger. The 25Ds are female. The pinout is odd. I don't have the pin numbers, but I can describe it.

 

The female D type is mounted so that the row of 13 pins is at the top, and the row of 12 at the bottom. Top left pin is Ch1, bottom left pin is Ch2, second along from the left on the top is Ch3, you get the idea. So the geography is that the pins are in exact physical order, but the numbers look weird. The top right pin is ground.