User's Manual

COBALT UHF-SERIES CHAPTER 5: COMMAND PROTOCOLS
PAGE 55 OF 140
C HECKSUM E XAMPLE
The following example depicts Command 0x05 (Read Data) when using a
Checksum.
COMMAND
ELEMENT
CONTENTS USED IN CHECKSUM
Header 0x02, 0x02 n/a
Command Size 0x0007 0x00, 0x07
Command ID 0x05 0x05
Start Address 0x0001 0x00, 0x01
Block Size 0x0004 0x00, 0x04
Timeout Value 0x07D0 0x07, 0xD0
Checksum
0x17
n/a
Terminator 0x03 n/a
Table 5-8: ABx Fast - Checksum Example
Add the byte values from the Command Size, Command ID, Start Address, Block
Size and Timeout Value parameters together and subtract from 0xFF. The resulting
value will be the Checksum.
[0x07
+ 0x05 + 0x01 + 0x04 + 0x07 + 0xD0] = 0xE8
The checksum equation is: [0xFF
– 0xE8] = 0x17
Checksum
= [0xFF –
(sum of
these fields)]