Chapter 5 – AT Commands, S-Registers, and Result Codes
Multi-Tech Systems, Inc. SocketModem MT5600SMI Developer’s Guide 48
Command: –STE= Set Telephony Extension
Description: Enables/disables Line-In-Use, Extension Pickup, and Remote Hangup
detection features.
Note: Additional hardware may be required to support these features.
Defined Values: The <value> corresponds to the selected bit-mapped options. T he bit fields
are defined as follows:
Bit 0 Line-In-Use detection enable/disable.
Bit 1 Extension Pickup detection enable/disable.
Bit 2 Remote Hangup detection enable/disable.
<value>
(Dec.)
Remote
Hangup
Extension
Pickup
Line-in-Use
0 (default) Disabled Disabled Disabled
1 Disabled Disabled Enabled
2 Disabled Enabled Disab led
3 Disabled Enabled Ena bled
4 Enabled Disabled Disabled
5 Enabled Disabled Enabled
6 Enabled Enabled Dis abled
7 Enabled Enabled Ena bled
Report Commands: -STE? Reports current values
Example: -STE: 4 Remote Hangup enabled, Extension
Pickup disabled, and Line-In-Use disabled.
-STE=? Reports available options
Behavior in Data Mode (+FCLASS=0):
When on-hook, if the line is in use and an ATDT is issued, the mod em will
not go off-hook and will return with the message LINE-IN-USE.
When off-hook and either an extension is picked up or a line reversa l is
detected, the modem will drop the connection. The disconnect reason in
register S86=25 (this is also defined for #UD). The user must flash the
hook in order to get a dial tone due because the remote server will be
retraining.
If the local handset is picked up while the modem is off-hook, the mo dem
will do a link-disconnect, flash the hook for 1.5 seconds, an d then connect
the local handset to the line. At this point, the user dial tone should be on
the local handset. The disconnect reason in S86=25.
Behavior in Voice Mode (+FCLASS=8):
When in voice mode and an extension is picked-up, a <DLE>P i s sent to
the DTE. When the modem is off-hook, a line reversal may also be
detected in which case a <DLE>l is sent to the DTE.
In voice mode, there is no blocking of ATDT when the line is in use. Al so,
there is no automatic hang-up in voice mode as in data mode. There is
only the above stated <DLE> shielding event reporting.
Operation in Data Mode:
Line-In-Use
(Enabled by AT-STE=1, AT-STE=3, AT-STE=5, or AT-STE=7)
Case 1: Telephone Line is in Use
If an ATDT, ATDP or ATDL is issued while Line-In-Use detection is
enabled and the telephone line is in use, the modem will immediately
return the message LINE-IN-USE to the DTE without going off-hook, and
then return to command mode.