Chapter 4 - V.22bis Commands
V.22bis Line Side Device Commands
| 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
Syntax
Defined Values
Range
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
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
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.
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