Panasonic AJ-D230HP operating instructions External interface specifications

RS-232C Interface

2. Software specifications

1) External interface specifications

Communication system	Asynchronous, full duplex
Baud rate	1200/2400/4800/9600/19200
Bit length	8 bit/7 bit
Stop bit	1 bit/2 bit
Parity	NONE/ODD/EVEN

The factory settings are 9600 bps, 8 bits, 1 stop bit, and none for the parity.

2) Sending format (from personal computer to VTR)

Data format

[STX] [discrimination] [:] [data] [ETX]

02H	XX XX XX	3AH XX XX 03H
	20H<XX<7FH	(XX = hexadecimal character code)
discrimination		: This is the command identifier (3 bytes).
		: This code serves as the delimiter between a command and data.
data		: Data codes are added when necessary.

1. A send command must always start with STX (character code 02H).

The ‘discrimination’which follows next is the command identifier. If necessary, data is added after the colon (" : ").

At the very end comes ETX (character code 03H).

2.When STX is re-sent before ETX is sent, the receive buffer inside the VTR is cleared (all data received up to that moment will be lost), and the data is processed again with the re-received STX placed at the head.

3)Receiving format (from VTR to personal computer)

The VTR responds to a send command with data in the following format.

1.First, the VTR returns the data which acknowledges whether the command from the computer was received properly.

1) The VTR returns the ACK data if communication was error-free.

[ACK]

06H

2)It returns data starting with NAK (negative acknowledge; character code 15H) if an error occurred in communication.

[NAK]

15H

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