Posted by Ujjal on 9/14/2006, 10:44 pm, in reply to "DMX questions after reading these pages" Here are some answers... 1)Take a look at these links http://users.skynet.be/kristofnys/ 2)MTBF and MTBP is not critical. Most recievers can handle minimum MTBF/MTBP...so keep it to as small a value as allowable by your code. 3)The transmitter can send any number of channels from 1 to 512(frames) in a single universe....it is upto the designer. You can , for instance, close at 250 channels by simply resending the BREAK (and fresh packet) after the 250th frame. 4)If U R talking about a transmitter..well why would U do that ? Would you design a desk with channel faders 1 to 12 missing ? 5)You got it right..sort of !! :-) 6)Just a suggestion ..... process code during BREAK. Toggle the line low and go into code proccessing. BTW , U don't have to stick to the 88 micros...that's the MINIMUM...for one of my transmitters I use 137 micros. Will work fine with all receivers. I know of commercial single CPU desks which have BREAKs upto 165 micros. Best practice is to use a dual proccessor and a dual port SRAM which is shared between the CPUs. That way , one guy is putting channel values into the RAM while the other guy is reading them off and generating DMX. 7)DMX512-A has a quite a few new features but is totally back compatible with 1990. It has been made more flexible and has been updated with the EIA-485 updations (which has also changed over the years). But the most significant change is the additional start codes (SC). But SC=0 is still fine for most DMX512 generation. To view the additional SC see this link 8)Right U are. We call that daisy chaining just as the garlands made by Grandma with daisy flowers ! :-) Hope that helps Ujjal
59.93.243.171
Hi
http://www.qsl.net/n5tle/
In case of a receiver , U need to have a start address selector like a DIP switch or equivalent.
You must try and use optos as well as transient protection diodes...well work well without these but that is not the recommended practice.
http://www.esta.org/tsp/working_groups/CP/DMXAlternateCodes.php
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