Net-2000™ Voice Codec Unit
User’s Manual
Page 17
Section 3 – Net-2000™ VCU Control
DVSI Confidential Proprietary
Voice Source
The Voice Source menu provides the user the choice to select which input source will be used on the
Net-2000™ VCU. The default source is set to Handset. Only one source may be selected at a time.
After switching from one voice source to another it is necessary to select the start button in order to
initiate the change.
Handset
4-Wire
2-Wire
Figure 11 Voice Source
Handset
When the Handset voice source interface is selected, the Net-2000™ VCU expects the analog voice
signal input and output on the RJ11 jack (Item 8 in Table 1 Rear Panel Connectors). The output will
also be on the output RCA jack (Item 6 Table 1 Rear Panel Connectors). The Net-2000™ VCU
outputs the audio to both the 4-Wire and Handset output regardless of which voice source is
selected.
4-Wire
When the 4-Wire voice source interface is selected, the Net-2000™ VCU expects the analog voice
signal input on the RCA jack (Item 7 in Table 1 Rear Panel Connectors). The unit outputs the analog
signal on the output RCA jack (Item 6 Table 1 Rear Panel Connectors). The Net-2000™ VCU
outputs the audio to both the 4-Wire and Handset output regardless of which voice source is
selected.
2-Wire
Before selecting the 2-Wire voice source the Net-2000™ VCU expects to be connected to a North
American POTS line. A industry standard telephone cord can be used to connect the wall jack to the
RJ11 jack (Item 5 in Table 1 Rear Panel Connectors). When the 2-Wire voice source interface is
selected, the Net-2000™ VCU automatically “picks-up” (opens) the line. When the voice source set
to 2-wire the incoming analog signal from the POTS line will be encoded and then output to the
selected channel interface (RS-422 or Ethernet). If the Ethernet loopback channel is selected then
the encoded speech will be decoded and sent out through the POTS line. The Net-2000™ VCU 4-
Wire and Handset outputs are not active. The POTS line can be hung-up (released) by selecting the
Stop VOIP button.
Output Gain
The output gain setting for the voice codec can be set by the user, however, the default values should
be sufficient for most applications. The Output gain can be set to -3dB or -6 dB.
Channel Source Selection
The Net-2000 can be configures to encode / decode speech from one of three communications
channel sources. The default channel is Ethernet loopback. Only one communication mode may be
selected at a time. After switching from one communications mode to another it is necessary to
select the start button in order to initiate the change.
Ethernet Loopback
Ethernet
RS-422 Asynchronous