Introduction; Set-Up; Conventions; Command And Response Formats - Arcam AVR550 Custom Installation Notes

Controlling via RS232/NET

Introduction

This document describes the remote control protocol for controlling via the RS232/NET interface. The AV implements virtual IR commands in order
to simplify the protocol. Any operation that can be invoked using the IR remote control can be achieved over a control link using the Simulate RC5 IR
command (0x08). See page 7 for details of this command. The RC5 IR code set is listed from page 26.

Set-up

The AV must be correctly configured for Control; by default, Control is disabled for minimum standby power consumption. RS232 control can be
enabled using the front panel: press and hold the front panel
Alternatively, Control for RS232 or IP can be enabled using the OSD menu. Press A followed by U on the remote control in order to access the setup
menu. Use the cursor keys < > , ' and O to enter the General Setup menu and locate the option Control. Press O , , then O to change
this parameter to 'On' . IP control is via port 50000 of the IP address of the unit (in the Network Settings menu).

Conventions

„ All hexadecimal numbers begin 0x.
„ Any character in single quotes gives the ASCII equivalent of a hex value.
„ <n> represents an unknown or variable number.

Serial Cable Specification

The cable is wired as a null modem:
Connector 1 pin Connector 2 pin
2 3
3 2
5 5

Data transfer format

„ Transfer rate: 38,400bps.
„ 1 start bit, 8 data bits, 1 stop bit, no parity, no flow control.

Command and response formats

Communication between the remote controller (RC) and the AV takes the form of sequences of bytes, with all commands and responses having the
same basic format. The AV shall always respond to a received command, but may also send messages at other times.
Each transmission by the RC is the following format:
<St> <Zn> <Cc> <Dl> <Data> <Et>
„ St (Start transmission): 0x21 '!'
„ Zn (Zone number): see below.
„ Cc (Command code): the code for the command
„ Dl (Data length): the number of data items following this item,excluding the ETR
„ Data: the parameters for the command
„ Et (End transmission): 0x0D
Each response by the AVR is the following format::
<St> <Zn> <Cc> <Ac> <Dl> <Data> <Et>
„ St (Start transmission): 0x21 '!'
„ Zn (Zone number): see below.
„ Cc (Command code): the code for the command
„ Ac (Answer code): see below.
„ Dl (Data Length): the number of data items following this item, excluding the ETR
„ Data: the parameters for the response of length n. n is limited to 255.
„ Et (End transmission): 0x0D
The AV responds to each command from the RC within three seconds. The RC may send further commands before a previous command response has
been received.
button for 4 seconds until "RS232 CONTROL ON" is displayed on the VFD.
DIRECT
Function
Rx  Tx
Tx  Rx
RS232 Ground
3