DMX512 SPEC OF data format of WAVEFORM

[longpole001]

mmm,

what RF module that encapsulate the DMX512 protocol , i was looking at using a RF protocol that is more robust even though it comes from other designs from a propitiatory use for messaging ,making any packet meet that protocol as there are so many that i looked at are way way better for the application than dmx512 ,

DMX512 appear to be well below par and waist full, even when used in wired app for the data sent , has no checking, no end of packet byte and high over head when less than 512bytes use , cos you have to know you not getting 512 bytes , not that you missed some and would fill the air with less than usefull retries to achieve an effect result.


I am new to some of this but it just seems that way to me

I also hate redoing the wheel even though the RF modulus i have dont have any protocol defined ( NRF 24L01 2.4Mhz )

any input be good as i am at a crossroads on the best way to proceed i need to control small amount of 600 lights with this app over a small area , of less that 1000 meters

l can make it work with any protocol as long as i can get the correct doco spec & it is not so left field that is not use full except for this application

cheers

[keithdoxey]

DMX512 appear to be well below par and waist full, even when used in wired app for the data sent , has no checking, no end of packet byte and high over head when less than 512bytes use , cos you have to know you not getting 512 bytes , not that you missed some and would fill the air with less than usefull retries to achieve an effect result.

I think you may have misinterpreted what DMX512 was designed to do. Its was specifically designed for control of lighting in a theatrical/club environment where lights are constantly changing. It is only wasteful if not properly configured.

The data packet consists of a header byte followed by a byte for each of the channels in order. As such it doesnt need any addressing info, the receiving device merely detects the header byte then count until the number of bytes received matches its configured address. There doesnt need to be a end of packet byte because there is a break in transmission between packets. The recieving device looks for the break, then header then counts.

Many DMX controllers use less than 512 channels, 54 or 192 channels being quite common. A 54 channel controller only sends 55 bytes per packet and as such can refresh lights about 9 times faster than a controller that addresses an entire universe.

DMX has been around a long time now and Im pretty sure that it would have been superceeded if it was as flakey as you appear to think it is. Good cable and correct termination makes for a robust system in what is often a very electrically noisy environment.