Serial Interface Protocol

 


Hardware interface:
DB-25 female "D" subminiature connector
9600 baud, no parity, 1 stop bit (8N1)
Both RTS and DTR modem control lines must be asserted.
The adapter loops RTS back to CTS, DTR back to DSR and DCD.


Software interface:
Each command consists of two bytes:

  b7 b6 b5 b4 b3 b2 b1 b0
Byte 1: 0 P1 P0 A4 A3 A2 A1 A0

b7 - - - - - - b0
Byte 1 = 0 P1 P0 A4 A3 A2 A1 A0,

where: P1 P0 is a port number
(01, 10, 11, or 00 for Port1, Port2, Port3, or all)
A4 A3 A2 A1 A0 is the machine address ("Category Code")
per Control-S standards

b7 - - - - - - b0
Byte 2 = 1 C6 C5 C4 C3 C2 C1 C0,

where: C6 - - - C0 is the command per Control-S standards
(Note that in Sony documents, the least significant bit is
usually to left, the most significant bit is to the right.)

The single Control-S cable of the RS-2/S1 is addressed as Port 1; the "all" address may also be used.

Each command successfully received by the adapter will be acknowledged by the adapter with a single 0FFh handshake byte. An error will be flagged with a single 0FEh handshake byte. The handshake is sent after the Control-S command is transmitted. Therefore, after receipt of the handshake, the host computer is free to issue subsequent commands.

Per Sony specifications, each Control-S command is sent three times, 45msec apart. (The adapter will do this automatically; the host computer only needs to transmit the command once.) From start of RS232 command transmission to end of RS232 handshake transmission, approximately 120 milliseconds elapse.

A received value of 0FFh causes the RS-2/S to keep the LED illuminated until a non-0FFh character is received. A 0FFh may be sent as the first character even though an error is generated (MSB is not '0'). This will cause the LED to illuminate and prepare the RS-2/S adapter to receive a proper message.


Examples:
To cause a VHS VCR addressed as "VTR3" on port #2 to go into PLAY, the command is:
Byte 1 = 4B hex (0 1 0 0 1 0 1 1)
Byte 2 = 9A hex (1 0 0 1 1 0 1 0)

To cause a VCR addressed as "VTR1" on port #3 to PAUSE, the command is:
Byte 1 = 62 hex (0 1 1 0 0 0 1 0)
Byte 2 = 99 hex (1 0 0 1 1 0 0 1)

To cause all VCRs addressed as "VTR2" on all ports to STOP, the command is:
Byte 1 = 07 hex (0 0 0 0 0 1 1 1)
Byte 2 = 98 hex (1 0 0 1 1 0 0 0)