Check Code - NEC V321-2 Communications Manual

4 ÿ Set Parameter reply
The monitor replies with this message for a confirmation of the "Set parameter message".
Message format of the "Set parameter reply" is as follows,
Result
STX
Hi Lo Hi

Refer to section 5.4 "Set parameter reply" for more details.
5 ÿ Command
"Command message" format depends on each command.
Usually, this "command message" is used for some non-slider controls and some special operations,
such as "Save current settings", "Get timing report", "power control", "Schedule", etc. Refer to
section 5.5 "Commands message" for more details.
6 ÿ Command reply
The monitor replies to a query from the controller.
"Command reply message" format depends on each command.
Refer to section 5.5 "Commands message" for more details.

4.5 Check code

Check code is the Block Check Code (BCC) between the Header and the End of Message except SOH.
D = D XOR D
n+1 1 2
XOR: Exclusive OR
Following is an example of a Check code (BCC) calculation.
Destination
SOH Reserved
Address
01 30 41
D D D
0 1 2
OP code
OP code
page
Lo Hi Lo
Header
SOH D
0
Reserved D
1
Destination D
2
Source D
3
Type D
4
Length(H) D
5
Length(L) D
6
STX D
7
Data D
8
| |
| |
ETX D
n
Check code D
n+1
XOR D XOR ,,, D
3 n
Header
Source Message
Message length
Address type
30 45 30
D D D
3 4 5
Type Max value
Hi Lo MSB
Check code
Message
7 6 5 4
2 2 2 2
P P P P
OP code
STX
page
41 02 30 30
D D D D
6 7 8 9
(5/37)
Requested setting
Value
LSB MSB
Delimiter
3 2 1 0
2 2 2 2
P P P P
Message
OP code Set Value
31 30 30 30 36 34
D D D D D D
10 11 12 13 14 15
ETX
LSB
Check
code Delimiter
ETX
(BCC)
03 77 0D
D D D
16 17 18