T and A Elektroakustik SACD-1245 Owners manual

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Technische Mitteilungen

RS232

The SACD1245 can be controlled by any control device having a RS232 serial output port (PC,
CRESTRON home automation system etc.) through the RS232/R-Link interface adaptor.

For details about connecting and operating the adaptor see the user manual of the adaptor
“UM_RS232_Adapt.doc”.

Settings for the RS232 interface of the control device are as follows:

Baudrate: 115.200
Data Bits: 8
Stop Bits: 1
Parity: none
Flow Control: none

control of the

SACD1245

T+A RS_232 Protocol

The SACD1245 uses the standard T+A RS232 command protocol as described in detail in the
documents “TA_RS232_protocol.doc” and “RS_232_Command_Codes.doc”.

Format of the command telegrams

A command telegram to the SACD1245 consists of 6 bytes. The complete telegram should be sent
without pauses between the bytes.

Example: SYSTEM_ON command

Byte 1 Byte 2 Byte 3 Byte 4 Byte 5 Byte 6
RS232
adaptor
Address

0x01 0x03

Byte 1, 2, 3, 5 : for the SACD1245 these bytes have the fixed values as shown in the table
below.

Byte 4 : R-Link command according to the table of RCII commands

Byte 6 : check sum == (byte1+byte2+byte3+byte4+byte5) modulo 0xFF

R-Link command
length

(R-Link address + R-Link
command + R-Link flag
byte = 0x03)

(see “RS_232_Command_Codes.doc”)

R-Link
Address

(0x22=CD)

0x22

(see below)

R-Link command

(here: SystemON = 0x57)

*see table
SACD1245 commands

0x57 0x02 0x7F

R-Link flag
byte

check sum

=

sum of bytes 1..5 mod.
0xFF

Format of the acknowledge (ACK) telegrams

The SACD1245 will process each received command telegram and it will send an acknowledge telegram approx.

25...35 ms after receiving the command.

The ACK telegram consists of 2 bytes:

Byte_1

is the RS232 address of the command telegram received before (=byte 1 of the command telegram =

0x01).

Byte_2

is the acknowledge byte. If this byte is equal to the check sum of the command telegram (byte6 of the
command) then the command was received correctly.
If byte 2 has a value different from the check sum of the command, an error has occurred (see table below).

Format of the ACK telegram:

Byte 1 Byte 2
RS232 address ACK byte

0x01

After the ACK telegram, the SACD1245 is ready for the next command.

= check sum of command: command correctly received
= check sum –1: command ignored (system busy)
= check sum –2: command not executed
Note:
If no ACK telegram is received within 35 milli-seconds after sending a command, there is either a

hardware problem (cable etc.) or the telegram is erroneous (wrong address, wrong check sum ....)

List of SACD1245 commands

Command Command

Code

(HEX)
ON_OFF 0x01 x better use discrete System ON + OFF codes
System ON 0x57
System Standby 0x77
System OFF 0x7A
CD/DVD 0x23
CD 0x45
PLAY 0x12
PAUSE 0x05
STOP 0x24
NEXT/UP 0x34 F10 cursor
PREV/DOWN 0x2A F10 cursor
FastForward/RIGHT 0x25 F10 cursor
FastBackwards/LEFT 0x1A F10 cursor
OK 0x26
00x03
10x3A
20x06
30x16
40x02
50x09
60x3B
70x31
80x11
90x39
F1/F2 0x32 x
F3/F4 0x0B x
F5/F6 0x36 x
Mono/Stereo 0x21 x same as F1/F2
Filter/Invert 0x2B x same as F3/F4

toggle Remark

Note: For a complete list of all R-Link source commands refer to the document
“RS_232_Command_Codes.doc”.