1. Serial Communications Basics
1.2
Data Words
msb
The
m
ost
s
ignificant
b
yte, is the byte with the greatest weight (value).
lsb
The
l
ess
s
ignificant
b
yte, is the byte with the smallest weight (value).
Description
A word contains more than one byte, the first byte is the msb, the last byte is the lsb.
Examples of Data Words
•
The projector runtime parameter is described using an unsigned double word where 2 bytes (msb ...lsb) represent the value of
the runtime in seconds.
How to calculate the value of a word ?
Lets take the example of a double word returned by the “
projector runtime, read
” commando.
returned data = Data[0]....Data[3]
value = Data[0]*256
3
+ Data[1]*256
2
+ Data[2]*256 + Data[3].
8
R5976538 BARCOREALITY SIM6 ULTRA SERIES 08/06/2005