T and A Elektroakustik DD-1535 Owners manual

TT Technical Information 7.09.2005

Telegram length

R-Link address

R-Link command

R-Link flag byte

Check sum

RS232 control of DD1535.

The surround decoder DD1535R with software version 1.31 or higher is compatible to be controlled by
any P/PA/R master device control device with software version 1.60 connected to a control-system
having a RS232 serial output port (PC, CRESTRON home automation system etc.) through the
RS232/R-Link interface adapter. The DD1535R cannot be controlled directly because it works as an
add-on for the master device. All surround related commands are passed on by the master device to
the surround decoder when in surround-mode. The DD1535R adds the Surround Control commands.
When the system is in surround mode it additionally takes over volume control and Loudness and
Tone control. The speaker output is tied to the speaker A.
For details about connecting and operating the adapter see the user manual of the adapter
“UM_RS232_Adapt.doc”.

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

Baud rate: 115.200
Data bits: 8
Stop bits: 1
Parity: none
Flow Control: none

T+A RS_232 Protocol

The R-series devices use 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 R-system master device consists of 6 bytes. The complete telegram
should be sent without pauses between the bytes.

Example: SYSTEM_ON command

Byte 1

RS232 adapter

address

(always 0x01) (R-Link address +

0x01 0x03 0xC8 0x57 0x02 0x25

Byte 1, 2, 3, 5 : these bytes have the fixed values as shown in the table above for all R-system

Byte 2

R-Link command +

R-Link flag byte =

0x03)

master devices

Byte 3

(0xC8=Amplifier/m

aster device

à see also note

below)

Byte 4

(here: SystemON =

0x57)

à see command

table

“appendix 1”

Byte 5

(always 0x02) = sum of

Byte 6

bytes 1..5

mod. 0xFF

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

Byte 6 : check sum == (byte1+byte2+byte3+byte4+byte5) modulo 0xFF
Note: The R-Link address 0xC8 is used for all standard amplifier commands. There exist a few

additional commands (system commands) for some special functions. For these commands the
address 0xC2 has to be used.

(see “RS_232_Command_Codes.doc”)

Format of the acknowledge (ACK) telegrams

If no ACK telegram is received within 35 milli-seconds after sending a command, there is either a

The R-System master device 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 master device 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:

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

Special System Commands

Beginning with version 1.31 the DD1535R automatically pushes the status information after it has changed.
Additionally the status can be requested by sending the command 0x64 (Status_1) or 0x43 (Status_2) to the

RLink-address 0xC2 but normally this should not be necessary. We strongly recommend to keep the

number of status requests low to avoid unnecessary RLink-Bus load. The information given is different for each
device and has to be decoded and displayed individually. For further information see the user manual ‘Crestron
T+A Macro’.

Responses of the DD1535R are as follows: