DMX Help

[tyler.martin]

I have a Strand Basic Palette hooked into an NSI IF501 converting DMX to MPX (which goes to our dimmers), and then from the DMX out on the IF501 I have it patched to 6 Coemar ProLed Lite's. We only have 24 Channels of dimming, so i have the Coemar's addressed from channel 30 onwards. However, I am not getting anything on the fixtures. When i plug the DMX into the A port on the board, they work fine, but when i use the DMX passthrough on the IF501 it doesnt work. Our Board has a DMX B output, but the Coemars cannot be addressed higher than 512, and i cannot map the 1st universe to both DMX ports. I need both the LED's and my conventional dimming to work off the same board at the same time, using light jockey or PC control is out of the question...

Any Ideas?

 

[avkid]

Use an isolated splitter before the DMX line goes into the converter.

For instance:
DMX Splitter

Also be sure to terminate the dimmer and the last fixture in the chain.

 

[JChenault]

I am not initmate with your board, and was not able to download the manual to take a quick look, but I think I hear some confusion about DMX addressing here.

You have a console with two output ports. ( Which you call A and B ). You can attach a DMX cable to port A, or attach on to port B.

If you look at the signal going across that cable, you will see data packets of 512 bytes. This is the data that is driving your dimmer or your Coemar fixtures. You cannot have an address greater than 512 going over the cable.

The industry typically refers to this range of 512 addresses as a universe.

The console has an idea of a 'output device' which on your console has an address of 1 - 1024.

How do you map the output device address to the 1-512 address range on a single cable? Typically you map 1-512 to port 'A' and 512 - 1024 to port 'B'

Sometimes these mappings can be changed ( not sure on your console)

As I see it you have two options.
1 - see if there is a way to map the 'B' output to output device address 1 - 512. IE port A would be outputting 1-512 and port B would be outputting 1-512 . I know this is possible on the ETC express line, I expect is should be possible on the Strand.
2 - Set up the coemar fixtures to use the output device address of 512 thru 1024 and plug them into port 'B'

The secret to 'B' is to subtract 512 from the consoles output device address to get the coemar DMX address to set the fixture to.

IE - if you map a coemar fixture with 4 channels to start at 550 ( higher than 512 so it will come out on port 'B') - set the coemar unit to start at 38 ( IE 550 - 512).

 

[soundlight]

I agree with the above - good example. You should easily be able to patch the outputs on the second universe to any channel you want. Then just plug the cable in to universe B. Universe B is a second 1-512 in terms of addresses on the fixture, but the console sees it as 512-1024. No DMX fixture can address to above 512 - the second universe is a repeat of channels, so you set the address, add 512 to it to get the "output" on the console (sometimes called the dimmer number), and then patch that to whatever channel you want.

 

[tyler.martin]

Thanks, I was just being stupid, The Strand OS does label the second universe 513-1024, and i couldnt wrap my head around that... That, and the DMX B port was not enabled... Thanks!