Control/Dimming Pathway Demultiplexer Troubleshooting


Active Member
I have a Pathway 1004 eDIN Demultiplexer (Rev 2) that either seems defective, or is set up incorrrectly.

The problem: In test mode (or normal DMX mode) it drives the output from 0-0.5v instead of 0-10v, I can't seem to get it to go to the full 10v.

It's being used to control 0-10v electronic fluorescent ballasts via DMX. This is a "sinking" application (confirmed since powering off the 1004 board results in the ballasts going to full and providing 10v).

I read the manual and everything is configured correctly as far as I can tell.

8 output channels from the board each have have 7 fixtures on it, and each fixture has 4 ballasts. I assume they're all wired in parallel. This has me slightly worried since if each ballast has a sinking current of 2ma, then total each channel would need to sink 56ma, more than the maximum of 30ma per channel. I don't necessarily know that the ballasts require 2ma each, but I can't seem to find specs about that (Advance Mark 7 izt-2t42-m3-ld). If it was just 1ma then I'd be good. I suppose I could measure this with a meter to be sure. Update: Found the correct datasheet - each ballast is 0.5ma sinking, so this shouldn't be a problem.

I have the DMX address set correctly, mode set to 1 (0-10v control), min set to 0, and max set to 158.

The diode shunts are enabled/on (manual: "With the shunts in the “on” position, the diodes are by-passed. This is the correct arrangement for sinking control of EFBCs [electronic flourescent ballast controls] and LED dimmers.")

The only thing I don't think I've tried is mode 8 - meant for EFBC control, but as far as I can tell from the manual it just sets output channels 9-16 as relays. I'll try this later today.

As far as the control wiring the gray (common/-) wires are ganged 2 up on the common terminals of the board (since there are 8 common wires but only 4 common connections), and then each purple (+) wire is connected to each channel. Could the common wires not being connected to the same block as the corresponding purple wires cause an issue? Here's a picture (click for full size):


Any ideas? This hasn't been working properly for as long as I can remember, and I don't know if it ever worked properly. I can't see the back of the board to visually inspect for any damage - I was worried about snapping the board when trying to take it out of the plastic case (I was able to remove it from the DIN rail, is there a correct way to remove the board from the case?).
Last edited:
I'd still try disconnecting all but on circuit and see if you got control.

No LEDs or other means to be sure the board is hearing DMX?

After that, good luck and hope one of the Pathway people hop in.
You're doing it the hard way. Now that you've got your facts straight, pick up the phone, call Pathway and avail yourself of their excellent tech support.
I've bugged them about long discontinued products and they have always gone the extra mile to provide answers and even service.
If you lift a purple wire off its terminal, you should measure 10V from the wire to any of the common terminals. If not, the control wiring isn't a complete circuit to the ballasts.

I could see an electrician assuming the control wiring is to be finished by others, or leaving it disconnected for initial heat up and forgetting to come back to it.
I've contacted Pathway and we're pretty sure the card is just defective. I'll either have to send it in for repair or buy another. Thanks for all the suggestions!

Users who are viewing this thread