Appendix B
7-1
7. Appendix B: Channel Bank with digital Monitoring Function
Channel Bank with digital Monitoring Function
Introduction
Among its many applications of the Loop-V 4200-9, an IAD (integrated access device), is a channel bank. In
this application, it will also have a digital monitoring capability, which is not available in a conventional
channel bank. Digital monitoring differs from analog monitoring in that (a) no tap on the voice circuit is
needed, avoiding any detection, and (b) the two directions of the conversation remain separated, providing
superior performance. This application note will describe the set-up for the channel bank application
including the monitoring function.
Of the 9 ports on the Loop-V 4200-9, the E1 plug-in card should go into Port A. This is because Port A is
wired to the bantam jack on the front panel, providing easy access to the E1 line for installation and
maintenance. The PORT A monitoring jack will monitor the E1 line, whereas this application provides for the
monitoring of any single voice channel within the E1. The other 8 ports each will have a QFXS (or QFXO
depending on the need) plugged in, resulting in 32 voice channels available, four from each Quad FXS plug-
in card. Since E1 uses 30 time slots for voice, the two extra voice channels (usually voice channels 3 and 4
of Port K) can be assigned for monitoring, one for each direction of conversation.
A
B
E
F
C
D
H
J
K
30 Voice Channels
2 Monitor Channels
E1 Line
Loop-V
4200-9
Loop-V 4200-9 Used as Channel Bank with Monitoring
The monitoring capability is derived from the “multicast” function of the Loop-V 4200-9. Multicast is an
operation where one time slot is mapped to many time slots.
Hardware
Install Loop-V 4200-9 according to instructions.
Install an E1 plug-in card into Port A of the Loop-V 4200-9.
Install 8 QFXS (or QFXO) plug-in card into Ports B, C, D, E, F, H, J, and K
Install a VT-100 terminal into the “console” port on the front of the Loop-V 4200-9.
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