Control/Dimming DMX Help

Hi: I'm relatively new to all this DMX stuff and I was hoping to get some help on a set-up I was planning.

We have an ETC Express 48/96 that will be doing all the DMX control.
We are hanging two I-Cue systems with a DMX Iris in each (on a S4). We will also have 8 color scrollers on some Shakespeares.

My questions are as follows:

1) Does every color scroller / DMX Iris / I-Cue need its own PSU or can one work for multiple accessories?
2) To have the Express interface with all the DMX Addresses can I have one cable running between everything and daisy chained together? (If that makes sense)

Thanks!

you can use one PSU as long as it big enough (has enough power), yes you daisy chain all the fixtures together

Thank you!

if you can aford it buy a PSU even bigger thatn what you need so when you buy more toys

EHansenLX said:

1) Does every color scroller / DMX Iris / I-Cue need its own PSU or can one work for multiple accessories?
2) To have the Express interface with all the DMX Addresses can I have one cable running between everything and daisy chained together? (If that makes sense)

Thanks!

Click to expand...

Single or multiple power supplies. I depends on the power suppl, and the power requirements of the strollers, etc. I would be surprised if they8 scroller so, two ICues, and 2 irises would work on one PSU. Add up the power requirements, and do the math.

Also note that the usual way these work is to send a DMX signal to the powee suppl(ies) and then run a different (4 pin) cable which puts power and DMX to the scroller. Wether or not you can daisy chain the schoolers, etc depends on the unit. If you can the usual recommendation is to daisy chain them in a loop. I.E. After the last scroller, you go,back to the power supply.

The DMX cable ( typically a 5 pin cable ) can be daisy chained ( with some limitations as to total cable length and number of devices) but at the last device you need to put a terminator.

So what I expect you will end up with ( assuming two power supplies ) would be:
From the console - a 5 pin DMX cable to PSU 1, then daisy chained to PSU 2, with a terminator at PSU 2

From each PSU a 4 pin scroller cable running between four strollers, the ICue, and iris, then back to the PSU. ( 7 cables ). ( making a lot of assumptions about your devices here ).

Note that some higher capacity PSUs actually consist of two smaller units. iE the Apollo 400 series is actually two Apollo 200 series units in the same box.

I would put different devices on different DMX chains, ie the 8 scrollers on one DMX split and power supply, and the two Icues and irises on another DMX split and power supply. Just me.

EHansenLX said:

Hi: I'm relatively new to all this DMX stuff and I was hoping to get some help on a set-up I was planning.

Click to expand...

The biggest point with the Iris, ICue, and especially scrollers is whether they're from compatible manufacturers. Power accessories like mirrors, iris, and scrollers get their power and data connection via power supplies or power injectors over 4-pin cables and not all manufacturers play nice with each other.

A lot of them use "Wybron Forerunner" as a default and many power supplies and gear are "Forerunner compatible" which means that you can usually safely plug together equipment from City Theatrical with stuff from Apollo and not have issues - BUT do not use ColorRAM or Cxi scrollers and/or power supplies with Forerunner power supplies or accessories unless you want repair bills. Of course Wybron made it even more complicated at the end by making "IT" series of ColorRAM and Cxi units that CAN run on the forerunner power connections. - fun right?

If you can verify that all your accessories run from the same power configuration then you just need to make sure that you're not overloading any one power supply - you need to also figure long cable runs causing power drops into that so just because you have a 600 watt power supply you can't run 600 watts of accessories over 600 feet of cable without problems - over 50 feet of cable might be fine. You can get an estimate of power draw here and maybe a better explanation here - "http://downloads.goapollo.com/SmartPowerFeature715.pdf"

The DMX part of your question is much easier - you can daisy chain DMX nodes all you want as long as there's enough signal to keep everyone on the cable loop happy. DMX specifications called for a 32 device limit per cable loop, but I've seen lots more devices than that without issues and I've seen 1/2 that with issues - and you should have some sort of DMX terminator on the last device in your DMX run - either internal termination or a good old fashioned DMX termination plug.

EHansenLX said:

Hi: I'm relatively new to all this DMX stuff and I was hoping to get some help on a set-up I was planning.

We have an ETC Express 48/96 that will be doing all the DMX control.
We are hanging two I-Cue systems with a DMX Iris in each (on a S4). We will also have 8 color scrollers on some Shakespeares.

My questions are as follows:

1) Does every color scroller / DMX Iris / I-Cue need its own PSU or can one work for multiple accessories?
2) To have the Express interface with all the DMX Addresses can I have one cable running between everything and daisy chained together? (If that makes sense)

Thanks!

Click to expand...

1.) No, provided a.) the power supply provides enough power b.) the maximum output cable length of the supply is not exceeded, and c.) everything uses the same pin outs. There are 2 competing, electrically incompatible scroller wiring schemes. I would start by pulling the manuals or data sheets for all your devices. I have a 150W PSU and a pair of I-cues pulls 34W, my irises pull an unknown amount, and I think my scrollers pull 10W each. I think I've got about 100W of load, plus the cable losses.

2.) Each DMX output needs to be a continuous chain. However, as far as the Express is concerned, everything hung off the 4 pin output of the power supply is on the same chain, even though it is technically a branch.