User's Manual

© SENSITECH INC. CONFIDENTIAL – CONTROLLED DOCUMENT Page 57 of 83
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PART NUMBER T82002163
REV A
Figure 1
Executes Command
Command
Echo back command
0x00 or
Parameter Packet
Status
HOST PC MONITOR
ULCM PACKET
COMMAND
PROTOCOL
Data Packet
Note: All data packets will consist of a 3 byte checksum position followed by
the requested data ending with a Checksum
The command parameter packet and data packet use the same packet format, which is shown
below:
Packet Data Checksum
3 byte count of the number of
parameters or data bytes to
follow
Parameter or Data bytes
B0 B1 B2 D0, D1, D2, D3, ……….Dn 1Byte
For instance if a ULCM command to download all the data is sent to the monitor, the monitor will send
(after the status byte) a packet containing a 3-byte value representing the number of data bytes to
follow, the data (which includes summary information and temperature data), and a checksum.
For any packet, the checksum is the least significant byte of the sum of all the data in the packet including
the 3-byte checksum position. This is shown in the example below: