Multi-Tech Systems MT2456SMI22 - Manual (Page 34)

Chapter 4 - V.22bis Commands
Multi-Tech Systems, Inc. MT2456SMI-22 SocketModem Developer’s Guide 34
V.22bis Line Side Device Commands
-TTE Threshold Adjustments for Telephony Extension
This command allows the host to set/tune the telephone line voltage level drop threshold necessary for the modem to
determine Line-in-Use, Extension Pickup, and Remote Hangup conditions. An ATZ or AT&F will load default values.
Syntax
-TTE=<Line-in-Use voltage drop threshold>,<Extension Pickup voltage drop threshold>, <Remote Hangup voltage
drop threshold>
Defined Values
Range =(0-9999), (0-9999), (0-9999)
Units: 1/10 volt
<Line-in-Use voltage drop threshold>
default: 1000 (10.00 V drop while modem onhook)
<Extension Pickup voltage drop threshold>
default: 200 (2.00 V drop while modem offhook) this value must be less than the Remote Hangup voltage
drop threshold
<Remote Hangup voltage drop threshold>
default: 500 (5.00 V drop while modem offhook) this value must be greater than the Extension Pickup
voltage drop threshold
AT-TTE? Queries current setting
Notes:
1. All thresholds are difference thresholds. Example: The line would be considered “in use” if the Tip & Ring Voltage
dropped by 10.00 volts. Another Example: If the modem is off hook and the voltage drops by more than 2.50
volts, then the modem would consider the condition as an extension pick up.
2. The <Remote Hangup voltage drop threshold> must always be less than the <Extension Pickup voltage drop
threshold). Otherwise, the extension pickup will not function.
-TRV Tip and Ring Voltage Measurement
This command measures and reports the telephone line voltage level at Tip and Ring while on-hook or in off-hook
command mode. If an application does not want to enable the telephony extension features through the –STE
command, the voltage value may be obtained using the -TRV command instead. This is also a very useful debug
command
.
Syntax
-TRV
Defined Values
Units: Volts
Response
xx.yy Example: A value of 30.50 indicates 30.50 V.
OK The lowest value reported by the modem is 1.40 V based on conversion formula.