Software specifications, 1) external interface specifications, 2) sending format (from personal computer to vtr) – Panasonic AJ-D230HP User Manual

Page 32: Rs-232c interface

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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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