Silicon Laboratories SI2493/57/34/15/04 - Manual (Page 251)

AN93
Rev. 1.3 251
V.90 modems must be tested with a digital modem, such as the USR Courier I. If a digital modem isn’t used as
illustrated in Figure 47, the highest connection speed a V.90 modem will support is 33.6 kbps. A call can be placed
or received in either direction at the speed set in the modems. A test script must be written for a computer to control
the dialing, monitor the call progress, send a file, and compare the received and sent files. Figure 47 illustrates this
test configuration.
Figure 47. V.90 Modem Functional Test Connection
Table 151 compares the coverage of &T2, &T3, and full bidirectional functional testing.
Table 151. Test Coverage
Circuit or Function &T2 &T3 Functional Test
Si24xx chip Yes Yes Yes
ISOcap Operation Yes Yes Yes
Si3018/10 Operation Yes Yes
Hookswitch Yes Yes
dc Termination Yes Yes
Bridge Yes Yes
AC Termination Yes Yes
Line Voltage Monitor Yes
Ringer Network Yes
Intrusion Detection Yes
Caller ID Yes
Overcurrent Detection Yes
Test
Computer
Teltone
ILS 2000
ISDN Modem
Modem Under Test
ISDN
Terminal
Adaptor
ISDN
ISDN Analog