Rear panel options, Intercom line termination (ms-704), Short-circuit and and overload conditions – Clear-Com MS-704 User Manual
Page 15: Rear panel options -9, Intercom line termination (ms-704) -9, Short-circuit and and overload conditions -9
M S - 7 0 4 / R M - 7 0 4 F O U R - C H A N N E L M A I N / R E M O T E S T A T I O N S
1 - 9
2. The auxiliary input connector has four individual program inputs for
each channel. These inputs cannot be disabled with front-panel DIP
switches.
REAR PANEL OPTIONS
This section describes the switches on the rear panel. These switches and controls
are usually set and not used in daily operation of the unit.
INTERCOM LINE TERMINATION (MS-704)
The MS-704 has switch-selectable intercom line termination networks. The
RM-704 is a remote station and therefore does not have terminating networks
available. If more than one MS-704 (or any other master station) is installed on
the same intercom line, then all of the terminations in all of the stations except
one must be disabled.
CAUTION: If the link function is to be used on an MS-704 and there is more than
one MS-704 in the system, it can only be used on the unit that provides
termination.
The terminations are enabled or disabled with switches on the rear panel. Each
channel is marked clearly on the panel. Set the switches to the off position to
disable the terminations in the station. The MS-704 is shipped from the factory
with all four lines terminated.
SHORT-CIRCUIT AND AND OVERLOAD CONDITIONS
If a short circuit condition appears on any of the four intercom lines, the sense
circuitry for that line will disconnect the DC power to that line only and the red
“short” light for that channel will be on. After as little as 1/2 second, the MS-704
will attempt to turn power on again. This allows momentary short or overload
conditions to clear automatically.
If the red “short” light remains after repeated automatic or manual attempts to
restore power, then there is either a short on that intercom line or too many
intercom stations have been connected to that intercom line. In this case, unplug
the intercom line connected to the affected channel and its red “short” light
should go out. This indicates that there is a short in that line. Follow that
intercom line and break it apart in several places while it is plugged into the
station to isolate the section of line that is shorted.