3M C860 User Manual

Model C960 Headset Intercom System
OperationandDiagrams
1-11E 3M 2000 May
Interconnect Module
An interconnect module is needed when a C960
Headset Intercom system includes an auxiliary
intercomtoprovidecontinuedcommunicationswhen
the primary intercom needs service.
The auxiliary intercom may be a conventional,
hard-wiredintercomorit maybeasecondC960base
station.
Externalsystemcomponents(speakers,microphone,
vehicle detector) connect to interconnect module
connector J302. Base station inputs and outputs
(power, common, menu mic, menu speaker,vehicle
detector) connect to interconnect module connector
J303. Auxiliary intercom (or second base station)
inputs and outputs connect to interconnect module
connector J301.
On/Off DC
In the interconnect module schematic diagram, the
interconnect module is shown in its “on” state, with
relays energized.
On/Offcontroloftheinterconnectmoduleisprovided
by (the presence or absence of) +12VDC from the
(primary) base station. With base station +12VDC
present (via J303 pins 1 and 2), relays K301, K302
andK303energizetoswitchmicrophone,speakerand
vehicledetectsignals to/from thebase station. Ifthe
basestation-providedDC isnotpresent (basestation
turnedoff),relaysK301,K302andK303de-energize
to the switch the same signals to/from the auxiliary
intercom.
Menu Microphone Signal Control
Relay contacts K301-A and K301-B control
distribution of the menu mic signal(s). With relay
K301 energized, the menu mic is connected to the
base station inputs. With Relay K301de-energized,
themenumic isconnected tothe auxiliaryintercom.
Menu Speaker Audio Control
Relay contacts K302-A and K302-B control
distribution of the menu speaker audio. With relay
K302energized,themenuspeakerisconnectedtothe
basestation. WithrelayK302de-energized,themenu
speaker is connected to the auxiliary intercom.
Monitor Speaker Audio Control
RelaycontactsK303-Bcontroldistributionofmonitor
speakeraudio. WithrelayK303 energized,thedrive
side of the monitor speaker is connected to the
monitorspeakeroutputofthebasestation. Withrelay
K303 de-energized, the drive side of the monitor
speakerisconnectedtothemonitorspeaker outputof
the auxiliary intercom. Monitorspeaker common is
not switched.
Vehicle Detector Signal DC
Whilethevehicle detectorispoweredseparately(ifit
isa“presence”type detector),vehicledetectorsignal
DC is always provided by both the base station and
the auxiliary intercom. This vehicle detector signal
DC is available at interconnect module connector
J302-9.
Avehicledetector signalDCof+12VDC isprovided
by the base station at J303pins 9 and 10. A vehicle
detector signal DC of +18VDC is provided by the
auxiliary intercom at J301 pins 1 and 7.
Ifboththe auxiliaryintercomandthebase stationare
ON, the vehicle detector signal will always be
+18VDC because the auxiliary intercom’s +18VDC
will take precedence over the +12VDC supplied by
the base station. (Isolation of the twoDC sourcesis
provided by interconnect module diodes D301 and
D303.) If only the base station is ON, the vehicle
detector signal DC will be +12VDC.

3M C860 Specifications

General

Brand	3M
Model	C860
Category	Intercom System
Language	English