NEC RS-232C Car Video System User Manual


 
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12. Serial No. & Model Name Read
12.1 Serial No. Read
This command is used in order to read a serial number.
1) The controller requests the monitor to read a serial number.
Header Message Check code
Delimiter
SOH-'0'-Monitor ID-'0'-'A'-'0'-'6' STX-'C'-'2'-'1'-'6'-ETX BCC CR
Header
SOH (01h): Start Of Header
'0' (30h): Reserved
Monitor ID: Specify the Monitor ID which you want to get serial number.
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'-'1'-'6' (43h, 32h, 31h, 36h): Serial No. 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 serial No. data to the controller.
Header Message Check code
Delimiter
SOH-'0'-'0'-Monitor ID-'B'-N-N
STX-'C'-'3'-'1'-'6'-
Data(0)-Data(1)---Data(n)-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".
N-N: Message length
Note.) The maximum data length that can be returned from the monitor at a time is
32bytes.
Ex.) The byte data 20h is encoded as ASCII characters '2' and '0' (32h and 30h).
Message
STX (02h): Start of Message
'C'-'3'-'1'-'6' (41h, 33h, 31h, 36h): Serial No. reply command
Data(0)-Data(1)----Data(n):Serial Number
These data are encoded to ASCII characters strings.
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