GAI-Tronics 69439-001 External Audio Interface (EAI) - Manual (Page 4)

Pub. 42004-677L2C
Model 69439-001 External Audio Interface Page: 4 of 9
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Contact Inputs
The contact closure input 1, contact closure input 2, contact closure input 3, and contact closure input 4
provide four supervised contact closure inputs to the system. Each input is activated by a switch closure.
The switch wiring is monitored for open or short circuit faults. A resistor network must be installed at the
switch to enable the cable monitoring. These inputs are typically used in conjunction with an audio input
and are used to assign a broadcast destination and a paging priority to the audio source. Actual wiring of
the input circuits is detailed on the connection diagram of the system control cabinet.
Figure 4. Typical contact input connection
Contact Outputs
The contact closure output 1, contact closure output 2, contact closure output 3, and contact closure
output 4 provide four voltage-free, solid-state contact closure outputs from the system. Each output can
switch a maximum load current of 50 mA. The output activation is controlled by the system MCU. The
activation times are defined by the system’s software programming. Actual wiring and operation of the
output circuits is detailed on the connection diagram and operating manuals of the system control cabinet.
N
OTE : If the EAI’s ON LINE LED is flashing, then all contact outputs will be open.
Figure 5. Typical contact output connection