Print Date 31/08/11 Page 17 of 22 E2136-00MA-02
2.4 : SERIAL REMOTE CONTROL AND MONITORING (/A and /T options only)
2.4.1 Introduction
When the /A option is fitted, serial control and monitoring is provided via a rear panel COM port
connector (section 2.2.6) using asynchronous data (1 start, 8 data, 1 stop bit, no parity) at 2400, 4800,
9600 or 19200 Baud. Control commands and status monitor requests are detailed in section 2.4.2.
The content of status monitor information reverted from the Amplifier is detailed in section 2.4.3. The
/T option also enables the same functions using TCP/IP via a rear panel RJ45 connector (section
2.2.7). Note that only one of these two options can be fitted.
The individual data bytes are defined in ASCII form, to enable basic control and monitoring using a PC
running a terminal program. However, a PC program with a dedicated textual and/or graphical user
interface is required for proper implementation of a remote control and monitoring system. Eddystone
Broadcast should be contacted for further information regarding such programs and hardware
implementations using the RS232 port directly or via USB or TCP/IP adaptors.
2.4.2 Control Commands and Status Monitor Requests
All command and status monitor requests are initiated by the remote control unit (PC) – the Amplifier
never outputs any serial data via the COM port or RJ45 connector unless requested to by that unit.
The remote control unit always sends a sequence of three bytes, waiting for each byte to be ‘echoed’
correctly before the next one is sent (which must be within 500mS of the previous one). A wait of
500mS is also recommended before the sequence is timed out and aborted. A new sequence of three
bytes then can be attempted. Note that an echo will not be returned when an invalid sequence is
detected by the Amplifier.
The three bytes are :-
First byte
‘Handshake’ (always ASCII #) – indicates start of sequence
Second byte
‘Command’ – indicates form of control or status monitoring
Third byte
‘Status Requests’ (after ASCII ? Command)
- gives details of status monitoring required
or
‘Controls’ (after ASCII + Command)
-
gives details of control required
Details of the Handshake, Command, Status Request and Control bytes are given in the following
tables. Typical examples of controller generated sequences are as follows :-
# ? 0
Request to revert the Output status
# +S
Sets Amplifier to Start/Unmuted
Handshake
(first byte sent from controller)
Title
Function
Hex
ASCII
Async_Hshake Remote input handshake
23
#
Remote Input Commands
(second byte sent from controller)
Title
Function
Hex
ASCII
Query_Status
Status query (request to revert)
3F
?
Amp_State
Amp state Mute or Start
2B
+
Remote Input Status Requests
(third byte sent from controller after
?
command)
Title
Function
Hex
ASCII
Op_Status
Revert output status
30
0
Amp_Status
Revert Amplifier status
59
Y
