NEC LCD Monitor, Manual

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14. Direct TV Chanel Read & Write
When DTV unit (Option unit) is installed, channel settings is read and write directly.
14.1 Direct TV Chanel Read & Reply
1) The controller requests the monitor to read channel information.
Header Message Check code Delimiter
SOH-'0'-Monitor ID-
'0'-'A'-'0'-'6'
STX-'C'-'2'-'2'-'C'-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".
'0'-'6'(30h, 36h): Message length
Message
STX (02h): Start of Message
'C'-'2'-'2'-'C' (43h, 32h, 32h, 43h): Direct TV Channel Read command
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'-'C'-
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'-'C' (43h, 33h, 32h, 43h): Direct TV Channel read 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