Ring Communications CB901EX - Manual (Page 21)

April 2012 Operations Manual CB901EX
TERMINATION OF AUDIO AND CONTROL SIGNALS TO PROGRAMME
DISTRIBUTION CARD NFE 1626.
One Subscriber Cable BF902 is used for termination to the Program Distribution Card NFE1626,
at the back of the Motherboard PCB979.
Flat cable no. 1 for audio signals to alarm- and program channels.
See Fig 1.18. for cable location and wiring details. The max. input level on alarm channel is 770
mV RMS (cable no. 1, pins 9A/B - 10A/B).
Flat cable no. 2 for control signals to alarm- and program channels.
See Fig. 1.18. for cable location and wiring details. The max. input level on program channels is
100 mV RMS (cable no 1, pins 1A/B - 8A/B)
To activate alarm channel no. 1 (top priority) 24V DC must be supplied to pins 32 A/B on cable
no. 2, positive to pin 32A. Audio signal from alarm source no. 1 (cable no. 1, pins 9A/B) will be
transmitted to all stations.
To activate alarm channel no. 2, 24V DC must be supplied to pins 31 A/B on cable no 2, positive
to 31A. Audio signal from alarm source no. 2 (cable no. 1, pin 10 A/B) will be transmitted to all
stations.
Alarm channels have top priority in the system. All other activity, program distribution, all-call,
group-call and normal calls will be overridden. Alarm channel no. 1 has priority over alarm channel no.
2. To deactivate an alarm channel the 24V DC «enable signal» must be disconnected (back to open
circuit on «alarm enable» input).
Battery Operation Function - cable no. 2. When CB901EX Systems are installed as no-break
system (connected to emergency power - battery bank) it is important to cut out the Program
Distribution Feature when there is a mains power failure. During this period, all stations using this
feature must be suspended from the program channels, otherwise the emergency battery could be
overloaded. Alarm channels will operate. Each station has a current consumption of approx. 150 mA.
When mains voltage returns, the stations will automatically be reconnected to the program channels. If
the Program Distribution «cut out» function is required, do the following:
1. Disconnect Diode D1 on Program Distribution Card NFE1626.
2. Install a separate small power supply/rectifier of 5 - 24V DC. Connect the output
voltage to the Battery Operation function, cable no. 2 - pins 30A/B, positive to pin
30A. See Fig. 1.18. for details.
When there is a mains power failure, the voltage (5-24DC) from the separate power supply is
missing and the Program Distribution function is disabled. Stations connected to the program channels
are canceled, but will be reconnected when mains power is restored.
NOTE. This function may also be operated by the management to allow for program listening
during lunch time, CoffeeBrakes etc.
Page 21 of 77
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