I was wondering if i could use the DMX-THRU output on my opto branch-4, as a "5th" output send along with the 4 iso split outputs without causing problems with signal???

Hi, I happen to own one of these fine pieces. I can tell you that you can only use the four outputs with the green led to send a dmx signal. The thru plug is for connecting to an additional splitter. Tap

TAP is correct.
However you should have both 3 and 5 pin outputs. If you get a 3 to 5 pin turn around you can actually use all 8 outputs making it an OPTO BRANCH 8. works great.

I realize this is an old thread, but in talking with a pro lighting guy from Nashville last night, I've come to believe that both "tap" and "Elation_Pro" are incorrect about the Opto-Branch 4.

1. You CAN use the DMX Thru port to continue on to other DMX receivers, but standard DMX rules apply (no more than 32 devices on the line, terminate the last fixture on the link, etc). The splitter is just seen as a receiver on the line; nothing more or less.

However, if something takes this line down, all the split lines will go down as well, so it's probably best to limit what is downstream of the Thru port. This is why we opto split in the first place... redundancy.

2. The manual gives every indication that there are only 4 isolators in the unit, not 8. Therefore, using both the 3-pin and 5-pin connectors from a single output actually amounts to using a DMX Y, which is not allowed by DMX standard. This *might* work but could potentially introduce issues.

I have to agree with you stoke. If I had been on the forums when you wrote this, I would have posted otherwise.

You are correct in that the thru port can be used to add other DMX devices, be it dimmers, movers, leds, or another split.

You are also correct in that you can use both the 3 and 5 pin outputs in a pinch on the same 'branch'. I have done it myself a few times, but would not recommend it. It was a last minute add of some equipment and no time to get another split.

2. The manual gives every indication that there are only 4 isolators in the unit, not 8. Therefore, using both the 3-pin and 5-pin connectors from a single output actually amounts to using a DMX Y, which is not allowed by DMX standard. This *might* work but could potentially introduce issues.

This is a good observation.. I am running this up the flag pole with our engineers.

Best regards,

Wow! This is my old thread. I did purchase this unit,and i HAVE used the "Thru" output,and doubled up on the 3 and 5 pin outs with absolutely NO PROBLEMS!!! This box is great because it allows me to split my fixture Stage left/right without having to run cross stage patches for my fixtures reducing the chances of somebody tripping on DMX cables!