NEC RS-232C manual Direct TV Chanel Write & Reply

14.2 Direct TV Chanel Write & Reply

1) The controller requests the monitor to write channel information.

Header	Message	Check code	Delimiter
SOH-'0'-Monitor ID-'0'-'A'-'1'-'2'	STX-'C'-'2'-'2'-'D'-MajorCH-MinorCH-ETX	BCC	CR
Header
SOH (01h): Start Of Header
'0' (30h): Reserved
Monitor ID: Specify the Monitor ID which you want to get Model Name.
Ex.) If Monitor ID is '1', specify 'A'.
'0' (30h): Message sender is the controller.
'A' (41h): Message type is "Command".
'1'-'2'(31h, 32h): Message length = 18bytes
Message
STX (02h): Start of Message	32h, 44h): Direct TV Channel write command
'C'-'2'-'2'-'D' (43h, 32h,

MajorCH: Major Channel (00000000h – FFFFFFFFh),

'0'-'0'-'0'-'0'-'0'-'0'-'0'-'0' ～ 'F'-'F'-'F'-'F'-'F'-'F'-'F'-'F'

MinorCH: Minor Channel (0000h – FFFFh),

'0'-'0'-'0'-'0' ～ 'F'-'F'-'F'-'F'

ETX (03h): End of Message

Check code

BCC: Block Check Code

Refer to the section 4.5 “Check code” for a BCC calculation.

Delimiter

CR (0Dh): End of packet

2) The monitor replies the result to the controller.

Header	Message	Check code	Delimiter
SOH-'0'-'0'-Monitor ID-'B'-'1'-'2'	STX-'C'-'3'-'2'-'D'-MajorCH-MinorCH-ETX	BCC	CR

Header

SOH (01h): Start of Header

'0' (30h): Reserved

'0' (30h): Message receiver is the controller.

Monitor ID: Indicate a replying Monitor ID.

Ex.) When this byte is set to 'A', the replying Monitor ID is '1'.

'B' (42h): Message type is "Command reply".

'1'-'2'(31h, 32h): Message length = 18bytes

Message

STX (02h): Start of Message

'C'-'3'-'2'-'D' (43h, 33h, 32h, 43h): Direct TV Channel write reply command

MajorCH: Major Channel (00000000h – FFFFFFFFh), '0'-'0'-'0'-'0'-'0'-'0'-'0'-'0' ～ 'F'-'F'-'F'-'F'-'F'-'F'-'F'-'F'

MinorCH: Minor Channel (0000h – FFFFh), '0'-'0'-'0'-'0' ～ 'F'-'F'-'F'-'F'

ETX (03h): End of Message

Check code

BCC: Block Check Code

Refer to the section 4.5 “Check code” for a BCC calculation.

Delimiter

CR (0Dh): End of packet

(71/72)