Full Detail can be found here on the wiki – http://wiki.everythingrobotics.com/index.php?title=Draft_Proposal
The trigger packet transmitted is 7 bytes long. Preamble(3 bytes), Sync(2 bytes), trigger command (1 byte) and CRC byte.
The Preamble is used by the the RF module to tune the Receiver.
The Sync word is used by the RF modules receiver circuit to know when a valid transmission is occuring and not just interference. This SYNC word can be used as a future PAN address, i.e. all your units are set to the same unique SYNC pattern then your units operating in the same area as other trigger units on the same frequency will not be triggered by your units and visa-versa.
If an invalid packet is detected by the CRC then the packet is dropped and the strobe will not fire. This is where some future work can be done with forward Error Correction, so a corrupt packet could be rebuilt and still used by the slave, i.e. the strobe could still fire even if some corruption is detected.
Currently the slaves so not communicate back to the master in anyway.