SRP-X500P RS-232C Interface Manual
1.7 Handshake Codes
ACK : 0x41 ( ‘A’ )
When the SRP-X500P has received a command from an external computer and has processed it successfully, it
returns an ACK to the computer as notification that the command has been executed. There are cases when other
data are added to and returned with the ACK, depending on the command.
See “2. Command Reference” (page 6) for details.
NAK : 0x4E ( ‘N’ )
When the SRP-X500P fails to process a command sent by an external computer, it returns a NAK to the
computer.
DELIMITER : 0x0D ( ‘CR’ )
The SRP-X500P adds a delimiter code (equivalent to the ASCII carriage return) as the last byte of all commands.
1.8 Communication Packet Format
Communication packets are variable in data length.
A communication packet consists of command, parameter and delimiter, as shown below.
Command example:
When “C” is selected in AV/RGB INPUT ( ‘C S E L 3 CR’ )
0x43, 0x53, 0x45, 0x4C, 0x33, 0x0D
Command Parameter Delimiter
Command
: The command always comprises the first four bytes.
Parameter
: The length and function of the parameter varies according to the command. See “2. Command
Reference” (page 6) for details.
Delimiter
: The SRP-X500P always adds the delimiter code 0x0D (equivalent to the ASCII carriage return)
as the last byte of all commands.
Example of ACK
When the SRP-X500P returns the status of the AV/RGB INPUT SELECT ( response to ‘R S E L CR’)
0x41, 0x33, 0x0D
ACK Parameter Delimiter
Parameter
: The length and function of the parameter varies according to the command. See “2. Command
Reference” (page6) for details.
Delimiter
: The SRP-X500P always adds the delimiter code 0x0D (equivalent to the ASCII carriage return)
as the last byte of all commands.
Example of NAK
0x4E, 0x0D
NAK Delimiter
Delimiter
: The SRP-X500P always adds the delimiter code 0x0D (equivalent to the ASCII carriage return)
as the last byte of all commands.
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