JVC SR-9240EK appendix VCR control commands

10. OPTIONAL SA-K97U RS-232C INTERFACE BOARD

10-3. SA-K97U RS-232C Protocol & Commands

This section provides technical data for programmers.

Command description

To use the commands described in the following pages, prepare the VCR for communications as follows:

Transmit the command “JVC TABLE 1 ON” (F6H) to the VCR. The VCR will return “ACK” (0AH).

The VCR can now receive any command described in this section. To cancel the communications mode, transmit the command “JVC TABLE 1 OFF” (F7H).

2-1 VCR control commands

Commands (1) through (12) are 1-byte commands. The VCR will return “ACK” (0AH) when the command is received. Confirm that “ACK” (0AH) has been returned before transmitting the next command.

(1)	OPERATE ON (7BH)	: VCR operating mode is turned “ON”.
	OPERATE OFF (7CH)	: VCR operating mode is turned “OFF”.
(2)	PLAY (3AH)	: Playback
(3)	STILL (4FH)	: Pause/Still
(4)	STOP (3FH)	: Stop
(5)	FF (ABH)	: FF/Forward search in the Play mode. (INDEX Search when Menu switch <INDEX SRCH> is set to
		ON.)
(6)	REW (ACH)	: REW/Reverse search in the Play mode. (INDEX Search when Menu switch <INDEX SRCH> is set
		to ON.)
(7)	REV PLAY (4AH)	: Reverse playback at normal speed
(8)	TIMER ON (60H)	: Timer “ON”
	TIMER OFF (61H)	: Timer “OFF”
(9)	OPE LOCK ON (69H)	: Operation lock “ON”
	OPE LOCK OFF (6AH)	: Operation lock “OFF”
(10)	EJECT (A3H)	: Cassette ejection
		VCR returns “ACK”, and then returns CASSETT OUT (03H) after cassette has been ejected.
(11)	F-FIELD STEP (ADH)	: Engages field advance when the VCR is in the Still mode. The tape is advanced by one field in the
		3H/Timelapse mode.
		If the VCR is in any other mode, the Still mode is engaged.
(12)	REC CHECK (C1H)	: Engages REC CHECK. (function is the same as when locally controlled on the VCR.)

Before transmitting either of the following commands ((13) or (14)), first transmit REC/DUB REQUEST (FAH), and confirm that “ACK” is returned by the VCR.

(13)	REC (CAH)	: Starts recording. The VCR returns “ACK”.
(14)	REC PAUSE (CBH)	: Engages Record-Pause mode. The VCR returns “ACK”.
		• To re-start recording, transmit REC (FAH+CAH).
		• To cancel Record-Pause, transmit STOP (3FH). The VCR will enter the Stop mode.

However, if the loaded cassette’s safety tab has been removed, recording is not possible regardless of the fact that “ACK” has been returned. Use the STATUS SENSE (D7H) command to confirm tape status. (See Section 2-3 (9)).

After transmitting commands VISS FWD (15) or VISS REV (16), transmit the appropriate numeric data (1-byte ASCII codes from 30H to 39H) and the data input command (40H).

ASCII codes “30H – 39H” correspond with the numbers “0 – 9” (ie.: 0: 30H, 1: 31H, ... 9: 39H).

Each byte of numeric data and the data input command should be transmitted separately with “ACK” (0AH) confirmation from the VCR after each transmission. The VCR’s Menu switch <INDEX SRCH> is set to OFF.

(15)	VISS FWD (B0H)	: To advance the tape in the forward search mode to the designated alarm-input point. The alarm
		point’s 2-byte numeric data should be input after transmission of this command.
(16)	VISS REV (B1H)	: To reverse the tape in the reverse search mode to the designated alarm-input point. The alarm
		point’s 2-byte numeric data should be input after transmission of this command.

Eg: To search for the 3rd alarm-input point from the current position.

TXD	B0H	30H		33H		40H			Time
RXD	0AH		0AH		0AH	0AH	Search start	01H (or 05H)

The VCR starts INDEX search after returning “ACK”. When the specified point is reached, the VCR returns COMPLETION (01H). If the end or beginning of the tape is reached before the specified point, the VCR returns NOT TARGET (05H). (Sending either the 30H,30H or 30H,31H command will cause the VCR to search for the 1st alarm-input point).

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