User's Manual

Alarm / Span Cabling
68P64115A19–4
Mar 2003
1X SC 4812T-MC BTS Hardware Installation - Software Release R2.16.1.x
CONTROLLED INTRODUCTION
2-14
Table 2-7: External Alarm Connector Characteristics and Requirements
Inputs Outputs
To ensure proper operation, each pair to be used must be
connected to an external sensor that provides a dry-contact
closure. The customer sensor output contacts between an
optically isolated 9V DC signal and an isolated return.
S 10k ohms or greater across the input pair is detected as an
open contact.
S 1k ohms or less across the input pair is detected as a closed
contact.
Either of the above states can be defined by the customer in
system software as an alarm condition.
The customer output device control inputs
connect between the common (COM) and
either the normally closed (NC) or normally
open (NO) contacts of a relay.
S Relay contacts are load rated for a
maximum of 1 A @ 24 Vdc and 0.5 A @
48 Vdc.
The toggling of the relay contacts to the
opposite state is controlled by system
software.
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