Table 5. Response codes
Code Description
0
Command executed successfully.
1
Bad command format. Returned if command syntax is not valid.
2
Bad command code. Returned if command code is not valid/does
not exist.
3
Bad checksum. Returned if checksum is not valid/does not match
calculated checksum.
4
Timeout. Returned if complete command packet was not received
within 2 seconds from receiving the tilde start character.
6
Unknown error. Used for internal purpose.
7
Communication error. Returned if null character 0x00 is received or
if internal buffer overflow occurred.
8
Bad parameter. Returned if any of the command parameters is not
valid.
9.3.
CRC checksum example
Note:
A checksum of “00” will bypass checksum field verification by the controller.
The command to be sent to the unit is 0x01 – SYS GET MODEL.
Full command is: ‘~ 01 01 XX’ + cr,
Where XX is an unknown command checksum at this time and ‘cr’ is ASCII
carriage return character.
Note:
This command assumes the unit address is set to 1.
To calculate command checksum, add decimal values of all characters in the
packet, excluding start, checksum, and terminator. Divide result by 256 and
the integer remainder converted to two ASCII hex digits is the checksum for
the command.
Table 6. Command CRC checksum
Characters
Value (Decimal)
Value (Hex)
space
32
0x20
0
48
0x30
1
49
0x31
space
32
0x20
0
48
0x30
1
49
0x31
space
32
0x20
Total = 290
Total = 0x122
Page 28
900035_B
900035_B - Serial communication
