COMSPHERE 3900 Series Modems
Test
The Test configuration options determine specifics, such as the duration of a test, for the various
diagnostic tests available to the modem.
Table 5-7 shows each Test configuration option as it appears on the LCD, with the Sync Leased
factory default setting (the default value if the modem is just being installed) shown following the
colon ( : ) on the first line and with all available selections listed on the second line. Following this
is a description of the configuration option. Factory default settings are listed in Appendix F.
DTE RL (CT140): Disable
Nxt Disable Enable
DTE Remote Loopback. Controls the use of Pin 21 of the EIA-232-D/ITU-T V.24 interface by the DTE to
initiate a remote loopback. An Abort command or test timeout ends this test.
This configuration option is not available if the LeasedLine Rate is configured for TMp.
H Enable
The DTE forces the modem into remote loopback when the signal on Pin 21 (ITU-T 140) is turned
ON. Remote Loop ends when the signal is dropped.
H Disable
The DTE does not initiate remote loopback in response to the signal on Pin 21.
The AT command is S-Register S51=n, where n is 0 for Disable and 1 for Enable.
DTE LL (CT141): Disable
Nxt Disable Enable
DTE Local Loopback. Controls the use of Pin 18 of the EIA-232-D/ITU-T V.24 interface by the DTE to initiate
a local loopback. An Abort command or test timeout ends this test.
H Enable
The DTE forces the modem into local loopback when the signal on Pin 18 (ITU-T 141) is turned ON.
Local loopback ends when the signal is dropped.
H Disable
The DTE will not initiate local loopback in response to the signal on Pin 18.
The AT command is S-Register S52=n, where n is 0 for Disable and 1 for Enable.
5-46
Table 5-7
(1 of 2)
Test Configuration Options
September 1998
3910-A2-GN32-40