20 replies to this topic

[Arthur Brown]

The one problem with cat 5 cable is that the usual cheap cable is thin gauge and single strand cores so it does not survive repeated re-use in hard environments. Used as command wires there is the need to calculate the volts lost to check that there will be enough current left to reliably fire what you want. -Here commercial ematches score as they are usually more sensitive than improvised ones.

[Pete B]

The one problem with cat 5 cable is that the usual cheap cable is thin gauge and single strand cores so it does not survive repeated re-use in hard environments. Used as command wires there is the need to calculate the volts lost to check that there will be enough current left to reliably fire what you want. -Here commercial ematches score as they are usually more sensitive than improvised ones.

Hmm I see... Good quality multicore cable seems quite expensive, I'm looking at a particular catalogue right now and some alternatives would be:

24 / 12 pair, cores are 24 strands @ 0.1mm, with foil/lapped screening - £6.85 p/m

24 / 12 pair, cores are 7 strands @ 0.2mm, double foil screening - £4.35 p/m

There is some bulk pricing options for 20+ and 100+ and at 100+ quantities the price goes down by more than £1 per meter.

[Arthur Brown]

The clever bit is to use a few cores say less than 12 (which keeps the cable requirements moderate) to send out a coded pulse sequence to fire specific cues or groups.

If you use 9 wires similar to a serial port system, you have 8 data lines and a signal ground line. This can be 2^8 = 256 separate cues. Is 256 cues enough?

There are systems sending power and data by FSK including bi-directional data and handshaking but to design one of these you have to have a lot of software and hardware experience.

DO the cubase bit hang the time code on it then uses the timecode to fire the dmx and pyro firing cues.

[Pete B]

The clever bit is to use a few cores say less than 12 (which keeps the cable requirements moderate) to send out a coded pulse sequence to fire specific cues or groups.

If you use 9 wires similar to a serial port system, you have 8 data lines and a signal ground line. This can be 2^8 = 256 separate cues. Is 256 cues enough?

There are systems sending power and data by FSK including bi-directional data and handshaking but to design one of these you have to have a lot of software and hardware experience.

DO the cubase bit hang the time code on it then uses the timecode to fire the dmx and pyro firing cues.

Ahhh wait a second, you're talking about making it completely digital arent you? Data lines.... That means each slat would need a decoder of some kind to send the electrical pulse to each terminal.

My initial concept was to have the Midi decoder in the master control box, the computer would send midi data via midi cable to the control box, the decoder then turns each note into an electrical pulse (upto 128) which goes to each relay, then 24v straight out to the slats.

Bit confused now. Dont get me wrong though 256 cues would be way better than 128. Though I'm not sure if I would use 128 anyway for the purposes of what I want to do with it. Hmm....

Edited by Pete B, 22 March 2008 - 04:34 PM.

[Arthur Brown]

Look at sending 9 cores of digital (slowly by modern standards!) round the field and pick them up wherever you want tapping out the channels you want for the cues you want to fire.

Digital round the site needs only a few cores. cues round the field means lots of wire.

Limited digital means one way comms and no continuity checking simple cues means easy continuity checking.

Edited by Arthur Brown, 22 March 2008 - 05:54 PM.

[Pete B]

Look at sending 9 cores of digital (slowly by modern standards!) round the field and pick them up wherever you want tapping out the channels you want for the cues you want to fire.

I dont think thats possible in Cubase, I would either have to write a VST plug-in or just use software like that HDFire LE.

Also wouldn't that mean I'd have to program a PIC chip for each slat to pick up the signal that was being 'tapped out'?