Product data

USRobotics
Command Reference
Data Command Set - 68
Response: +ITF: (<off> range),(<on> range),(<report_period> range)
Example: +ITF: (20-7000),(10-5000),(0)
Diagnostic and Test Commands
#UD - Last Call Status Report
#UD is an action command requesting reporting of logged operation events. It
does not take parameters and must be the last command in the command line.
The modem logs aspects of their operation for each call, and saves these results
until cleared by one of the following events:
Power off
Hard reset (e.g., negate DTR with &D3 set; reset button)
Soft reset = ATZ or AT&F
ATD command issued
ATA command issued
Automatic answer (e.g., set register S0>0 and ring detected)
These results are NOT cleared by changing DTR, V.24 circuit 108.2, if &D0, &D1
or &D2.
Data Call State Model
For purposes of this command, there are four data call states, and associated
status issues:
Call Setup - Calling DCE: get dial tone, generate dial digits, detect call progress
signals. - Answering DCE: detect ringing, detect CallerID, etc.
Negotiation - V.25 calling tone/answer tone exchanges - V.8 or V.8bis call
function negotiations - V-series modem carrier detection and training - Modem-to-
modem protocols (e.g., V.42, V.42bis).
Data Transfer - Bit-error rates, for each direction - Rate renegotiation - Retraining
Call Termination
- protocol disconnect signals
- carrier disconnect signals
- loss of carrier
- excessive error rates