Reference Monitors User Handbook
39
REFERENCE MONIT
ORS RM-4C8
REFERENCE MONITORS RM-4C8
2
The Audio Underlevel alarm is triggered if either currently selected input Source remains
below -20dBu for longer than 20 seconds.
The Sustained Phase Error alarm is triggered if the phase difference between the two
currently selected input Sources remains consistently above 90 degrees for longer than
5 seconds.
The AES/EBU Lock output is a real-time (non-latching) status output which becomes
active if a valid AES/EBU signal is detected. By default, the open-collector output is low
(conducting) when a valid AES signal is detected on either of the currently selected Source
inputs. However, the polarity of the output may be reversed and/or a requirement imposed
that a valid signal be present on both currently selected Source inputs using the serial
remote control LCK: command.
The active-low control inputs all have internal pull-ups. Equipment driving these inputs
need sink only 1mA and block 5V.
The MUTE input mutes the loudspeakers, headphone output and line outputs while held
low. The front panel CUT L and CUT R buttons illuminate to indicate that MUTE is asserted.
The SPEAKER MUTE input mutes the speakers in the Reference Monitor. Audio is still
present at the headphone and line outputs and the front panel modifiers affect this audio
as normally.
Note: this function is operational from firmware version V1.116 and onwards.
The DIM input reduces the loudspeaker/headphone level by 10dB while held low (for
example, whilst an external talkback system is active). The front panel DIM button
illuminates to indicate that DIM is asserted.
Asserting the Alarm Reset input by pulling it low resets any active Alarm outputs to their
untriggered states and allows them to monitor for new alarm conditions.
RS232 Remote Control
A 9-way female D-type connector carries a standard RS232 interface via which advanced
configuration options may be set and many functions may be remotely controlled. The pin
assignations are as follows:
Pin 2:
Data transmit
Pin 3:
Data receive
Pin 5:
Ground
All other pins are unused.
The RM-4C8 will interface directly with personal computer serial ports at standard RS232
signal levels using a straight-through cable. The data format is 19200 baud with 8 data bits,
even parity and 1 stop bit. XON/XOFF flow control is used when necessary.
Sonifex SCi software, when installed on a suitable PC, provides straightforward graphical
access to all remote control and configuration options via both RS232 and USB interfaces.
Alternatively, commands may be issued from any text-based terminal program
(e.g. Hyperterminal) or custom software may be developed for specific requirements.