Carrier Access Access Bank II SNMP - Manual (Page 95)

Battery Reversal FXS & Dial Pulse Origination Card
9-22 9/24/01
9.7 Setting BRFXS and DPO
9.7.1 Battery Reversal FXS Loop-Start
The BRFXS/DPO card includes a setting for 2-wire FXS loop-start operation with battery reversal.
To enable this option, set Switch A on the 4-position DIP switch to ON so that cadenced ringing volt-
age is applied to the CPE loop during an incoming call (See Table 9-2). The battery is reversed during
this time. If desired, Switch B can be turned ON also to send a cadenced (2-second/ 4-second) ring-
back tone to the T1 line during incoming calls.
9.7.2 Dial Pulse Origination (DPO)
The DPO option is selected by setting Switch A to OFF so that no ringing voltage is applied towards
the CPE. If desired, Switch B can be turned ON to give a cadenced (2 second/ 4 second) ringback
tone to the T1 line during incoming calls (See Table 9-2). To indicate an incoming call, the battery to
the CPE loop is reversed. When the call ends, the battery returns to forward.
9.7.3 BRFXS/DPO Voice Channel Monitoring and Testing
The channel status LEDs on the back plate of the Access Bank II allow you to monitor the individual
BRFXS/DPO voice lines. The meaning of these LEDs is summarized above in Figure 9-4.
The channel test switches on the BRFXS/DPO back plate can be used to apply reverse battery to the
CPE loop and send A/B bits forced to 1/1 toward the T1 network. If Switch A is ON, 4 seconds of
continuous ringing voltage (85 V) are sent to the tip and ring pair of each BRFXS/DPO voice chan-
nel. In this case, you can check the operation of an individual voice channel by attaching a test tele-
phone to the Tip and Ring pair of that particular channel at the punchdown block or RJ-11
Harmonica, then switching ON the appropriate channel test switch to test that channel. If Switch B is
ON, 4 seconds of continuous ringback tone is also sent to the T1 network.
9.8 Busying Out Individual BRFXS/DPO Channels
If Switch A and Switch B are both ON, setting a channel test switch to ON has four results on the
selected channel:
1. Reverse battery is applied to the CPE loop and the A/B signaling bits sent to the network are
forced to 1/1.
2. To confirm individual channel circuit integrity, 4 seconds of continuous ringing voltage are
sent to the Tip and Ring pair. The Tip is then grounded until the channel test switch is turned
to the OFF position (to the right).