AT&T 76450 manual Tbos/Tabs

Common Systems Connection Standards		AT&T Services, Inc
Date: August 31, 2007		ATT-TP-76450, Issue 9
	(TBOS/TABS)
	E2A Discrete	Least Preferred

Footnote: A discrete telemetry interface may be provided, on an optional basis, in addition to higher level interfaces, to provide a summary of alarm and status information for remote surveillance.

4.6 Alarm Interconnection:

Each NE in a bay shall produce its own unique set of alarm outputs. Pre-designed “busing” of alarms or alarm leads within a bay is at the discretion of AT&T and shall not be mandated by the equipment design.

•The interface for TL1 interconnection may be Ethernet RJ45, DB25 or RS422/449 (37 Pin).

•The interface for E2A Serial or Discrete interconnections may be wire-wrap pins or other non-proprietary connector.

Discrete Alarm Conditions:

4.7 Discrete Alarm Rating

Minimum current carrying capacity - steady state: 0.9 amps at 60 volts for -48 volt applications.

Minimum current (20 msec. duration) during initial contact closure: 0.9 amps at 60 volts for -48 volt applications.

4.8 Open discrete alarm outputs

All discrete alarm outputs shall be designed to provide both normally open (closed when corresponding

failures are declared by the system) and normally closed (opened when corresponding failures are declared by the system) alarm outputs. The use of Form-C relays may be used to provide this capability.

4.9Discrete alarm paired leads

All discrete alarm outputs shall be paired leads (tip and ring) with no common or shared return leads.

4.10Discrete alarm dry contacts

All discrete alarm outputs shall be electro-mechanical (non-solid state) dry relay contacts without any type of constant voltage source or current flow present in a normal or failed state.

Copyright ©2004 – 2006, AT&T Knowledge Ventures

All rights reserved

Page 15