NEC RS-232C user manual Check code, Msb Lsb, Soh

Message format of the “Set parameter” is as follows,

STX	OP code			OP	code		Set	Value		ETX
		page
	Hi		Lo	Hi		Lo	MSB		LSB

Refer to section 5.3 “Set parameter” for more details.

4）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,

STX

Result

OP code

OP code

Type

Max value

Requested setting

ETX

page

Value

Hi

Lo

Hi

Lo

Hi

Lo

Hi

Lo

MSB

LSB

MSB

LSB

Refer to section 5.4 “Set parameter reply” for more details.

5）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）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

Header Message

Check code

Delimiter

Check code is the Block Check Code (BCC) between the Header and the End of Message except SOH.

SOH	D0	27	26	25	24	23	22	21	20
Reserved	D1
Destination	D2
Source	D3
Type	D4
Length(H)	D5
Length(L)	D6
STX	D7
Data	D8
ETX	Dn
Check code	Dn+1	P	P	P	P	P	P	P	P

Dn+1 = D1 XOR D2 XOR D3 XOR ,,, Dn

XOR: Exclusive OR

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