Barco BarcoGraphics Maxwell/ 6300 User Manual page 18

n
Checksum byte :
The "checksum byte" is used to detect errors during
transmission or reception.
Formula :
Checksum byte
= (Projector address + Command bytes + Data bytes) modulo 256
n
Stop byte :
The "stop byte" informs the projector (in case of
transmission) or the computer (in case of reception) that
the data transfer is complete and that the interpretation of
the command and data bytes can start.
Any command byte, data byte or checksum byte
that equals \x80, \xfe or \xff has to be converted !
Transmission :
- Instead of \x80, send \x80 followed by \x00.
- Instead of \xfe, send \x80 followed by \x7e.
- Instead of \xff, send \x80 followed by \x7f.
Reception :
- Replace \x80 followed by \x00 with \x80.
- Replace \x80 followed by \x7e with \xfe.
- Replace \x80 followed by \x7f with \xff..
18