Measurement Computing CB-COM-7013 - Manual (Page 15)

15
CB-7013, CB-7033 User’s Manual
2. Command
Command Format; (Leading)(Address)(Command)[CHK](cr)
Response Format: (Leading)(Address)(Data)[CHK](cr)
[CHK] 2-character checksum
(cr)
end-of-command character, character return (0x0D)
Calculate Checksum:
1.
Calculate ASCII sum of all characters of command (or
response) string except the character return (cr).
2. Mask the sum of string with 0ffh.
Example:
Command string: $012(cr)
Sum of string = ‘$’+‘0’+‘1’+‘2’ = 24h+30h+31h+32h = B7h.
The checksum is B7h, and [CHK] = “B7”.
Command string with checksum: $012B7(cr).
Response string: !01200600(cr).
Sum of string: ‘!’+‘0’+‘1’+‘2’+‘0’+‘0’+‘6’+‘0’+‘0’
= 21h+30h+31h+32h+30h+30h+36h+30h+30h = 1AAh
The checksum is AAh, and [CHK] = “AA”.
Response string with checksum: !01200600AA(cr).