Handshake codes, Communication packet format, Andshake – Sony SRP-X500P User Manual

Page 5: Odes, Ommunication, Acket, Ormat, 7 handshake codes, 8 communication packet format

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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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