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. The 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 Disabled
3 Disabled Enabled Enabled
4 Enabled Disabled Disabled
5 Enabled Disabled Enabled
6 Enabled Enabled Disabled
7 Enabled Enabled Enabled
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 modem 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 reversal 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 modem
will do a link-disconnect, flash the hook for 1.5 seconds, and 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 is 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. Also,
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.