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=,, drop threshold>
Defined Values
Range =(0-9999), (0-9999), (0-9999)
Units: 1/10 volt
default: 1000 (10.00 V drop while modem onhook)
default: 200 (2.00 V drop while modem offhook) this value must be less than the 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 must always be less than the
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.