Multi-Tech Systems MT5600BA-V92 User Manual

Chapter 2 – AT Commands

Multi-Tech Systems, Inc. AT Commands Reference Guide (S000273G)

Call Control Command

Command: -STE= Set Telephony Extension

Description:

This command enables/disables Line-In-Use, Extension Pickup, and Remote Hang up
detection features.

Note:

Additional hardware may be required to support these features.

Syntax:

-STE=<value>

Values:

<value> Decimal number corresponding 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 Hang up – detection enable/disable.

<value> (decimal)

Remote Hangup Extension

Pickup

Line-in-Use

0 (default)

Disabled

Enabled

Disabled

Enabled

Disabled

Enabled

Disabled

Enabled

Disabled

Enabled

Disabled

Enabled

Report Commands:

-STE? Reports current or selected values

-STE=? Reports supported range of parameter values

Result Codes:

OK <value> = 0-7

ERROR Otherwise.

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 (also defined
for #UD). The user must flash the hook in order to get a dial tone because the remote
server will be retraining.

If local handset is picked up while modem is off-hook, modem will do a link-disconnect,
flash the hook for 1.5 seconds, then connect local handset to the line. Now, the user dial
tone is on the local handset. Disconnect reason 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.

Case 2: Telephone Line is in Use But Disconnected

If an ATDT, ATDP or ATDL is issued while Line-In-Use detection is enabled and the
telephone line is NOT in use, the modem will go off-hook after a short pause, then
respond with CONNECT or NO CARRIER message.

Case 3: Telephone Line is Not Connected to Modem

If an ATDT, ATDP or ATDL is issued while Line-In-Use detection is enabled and the
telephone line is not connected, the modem will go off-hook momentarily, go back on-
hook, then respond with NO DIAL TONE message.

Extension Pick-up (Enabled by AT-STE=2, AT-STE=3, AT-STE=6, or AT-STE=7):

Case 1: Modem off-hook, Local Handset Goes Off-Hook

If the local handset goes off-hook while the modem is in a data connection, the modem
will then send a GSTN Clear down to the remote modem and then go on-hook. The
modem will then send a NO CARRIER message to the DTE. A result code of 25 will be
left in S86 register.