DMX Splitters and Mergers

I generally speaking wouldn't try to merge two asyncronous signals and multiplex them onto one line with the idea of making two DMX-512 streams co-mingle into ONE single coherent stream.

(This is as opposed to say muxing multiple terminals or modems, then running that down a T1 then reverse muxing it out at the other end, in which case all async streams are kept sepparate despite travelling down one consolidated cirucit)
(Hell, it ain't even the same as using a CSU to break off voice or data channels off a T1 and direct those into a PBX, since that would most likely be a partially channelized circuit, or at least the voice channels would be).

But they do make DMX mergers, so there. I wouldn't use it. I can see the need, but I see a bigger need for the proper equipment from an operations perspective first, which would eliminate the need for a merger in the first place.

Regardless, sure, take that into an Opto Branch 4 and send duplicate signals in up to 5 different directions(they say 4, you can do 5, in face you can do 10 if you use DMX 3 to 5 wire converters as necessary).

Based on descriptions, the DM-2512R would be the merge device, and then you'd patch that to the OptoBranch 4 and then you can split that up to 10 directions(using adaptors as needed).

I suppose short of getting another console to do the tasks of those two lesser consoles, this could work fine. I personally wouldn't do what you're doing, but it would appear you've selected the right gear and it should work fine.

Well thanks for the quick reply. Because I was reading up on the DM2512R, it was saying you can either use it in HTP, Backup, or Merge. But what I was thinking of using for is, because I am getting MyDMX I was going to have my DMX70 as a backup in case something goes wrong during an event. Either that or like my earlier example has stated using the two consoles and merging them. But the splitter part was what I was wondering about after the merge, because I am going to invest in Wireless DMX units so I am not running dmx lines to each different setup then looping through to another setup. I figure the splitter would be easier with the WDMX then to run loops.

You can indeed use a DM2512R and then a splitter after it. The OptoBranch 4 however can only run 9 DMX outputs. Each section has a group of isolated 5 and 3 pin outputs. Both of these outputs have there own DMX drive behind it. The DMX Thru however is a parallel out just like the DMX In. So you can't run a 5 pin and 3 pin signal into it and/or thru it. Just one cable in and one cable thru. So total outputs would be 9. You can however use the In and Thru as a turnaround.

Be aware that the 5 pin and 3 pin connections in each section aren't isolated from each other. This means issues that arise on the one will effect the other. Also, something that takes out the chain on that section can take out the chain on the other output in that section as well.

Since I run MyDMDX quite litereally by placing that laptop on the same rack that has the DMX Operator and the OptoBranch/4, if I have a fail-over, I simply swap the cable from the OptoBranch/4 input. I have a cable wired to the DMX Operator and a sepparate cable(loose) to the MyDMX dongle. My switch-over takes seconds. The argument for a fail-over solution is entirely valid and it is a justifiable concern for those using computer/PC-based solutions, as opposed to dedicated hardware.

I figured the pairs of outputs would be in parallel. The unit is advertised and in the manual states it is a 4-way split system. The fact that it CAN drive that many outputs is just something a few people have taken advantage of. For me, it's almost an ideal unit. I can send a run back behind me, a run to the stage, and then another 2 runs often side to side for follow spots and keep it clean.

I'd ideally like another one at the stage. Floor/footlights run, front truss, rear truss. Anything off the sides can hang off the front or rear truss runs, leaving me an open split in case anything crops up.

That outputs, that is A, B, C, and D, are paralleled at isolation into separate DMX drives for the 5 pin and 3 pin. The DMX Thru is paralleled after the DMX drive and thus can't use the 5 pin and 3 pin output at the same time. Likewise, the input is paralleled. So you can use all 8 connections on the front, four 5 pin and four 3 pin, but 5 pin and 3 pin aren't isolated on each section, be it A, B, C, or D. The sections are isolated from each other.

It is also important to note that if something takes out/effects the line on the DMX Thru, it will take it out/effect it all the way back to the console. This is why they say only use other splitters on the DMX Thru.

Makes sense. I don't see this as a design shortcoming, but rather a design necessity to ensure as clear a channel from the source to further down the line.

Of course, I do realize each set of outputs is a parealleled connection. Otherwise the cost of the box would probably be tripled.

Ok so I got my Elation DMX Branch 4 in but have concerns. When I plug it into MyDMX both the red light and green light lights up/ becomes solid on the splitter for all the channels, instead of just one pin. Unless I am misunderstanding the directions for the unit.

quote:

Indicators:
Each of the four output channels have a set LED indicators, a
red and a green. Without an incoming DMX signal the red LEDs
will function as a power indicator. When a DMX signal is applied
the LED’s will serve two functions:
1. These indicator will indicate pin polarity. A solid red LED will
indicate pin 3 is hot (positive). A solid green LED will indicate
pin 2 is hot (positive).
2. When shorted or bad cable is connected to a particular channel
the LED will turn off. This is useful to immediately identify
bad cables or lines.

So does anyone else have this issue or is it just me.

i THINK your good to go. did you hook a cable up and see if they send DMX? If they do then your solid.
Sincerely,

Well see that is where I am confused at. It works perfectly, well even better that the signal is now boosted. My lights respond faster now. But I was confused on the indicator lights part because now I can't really explain to others how it works, because it does not follow the manual. So am I understanding it correctly that MyDMX will do that with the splitter/booster? Because what the lights tell me is that the positive(hot) is on both lines. I am so confused.

You are good to go. When the unit sees DMX signal, both the green and red LEDs should be on. The green might also blink a little bit as well. The manual is miss printed and should read that one LED is positive and the other negative.

Well this is from the latest manual from the elation website.

quote:

Indicators:
Each of the four output channels have a set LED indicators, a
red and a green. Without an incoming DMX signal the red LEDs
will function as a power indicator. When a DMX signal is applied
the LED’s will serve two functions:
1. These indicator will indicate pin polarity. A solid red LED will
indicate pin 3 is hot (positive). A solid green LED will indicate
pin 2 is hot (positive).
2. When shorted or bad cable is connected to a particular channel
the LED will turn off. This is useful to immediately identify
bad cables or lines.

The manual online is the same as the printed one. I'll see if i can get them to update it.
Sincerely,

If I remember correctly, it is actually labeled on the face on the unit as well as one being positive and the other negative.

Edit: Yes, red LED is positive and green LED is negative. Took out on of my units just now and confirmed. Red will be lit with something connected to it unless there is a short. Green only comes on when the unit sees DMX signal. Makes sense since electricity flows negative to positive and the signal comes from the DMX controller. (Yes, I know in school they said electricity follows positive to negative, well they lied. It is the electron (negative) that moves, not the proton (positive). Drove me insane in school since I did it negative to positive and the drove the teachers nuts. /rant)