Table of Contents
Advertisement
Revised 2018-12-10
Drawing No. LP1087-A
2.5 Maintenance Information
2.5.1 Troubleshooting Tips
2.5.1.1 VT‐MODEM Default LED Indications
LED
Carrier Detect
Data Terminal Ready
Receive Data
Transmit Data
Power LED
2.5.1.2 Reconnecting Serial Cables
It is important to cycle (remove and then reapply) DC power to a VT-MODEM-4 each time the RS232 cable is
disconnected and then reconnected. The serial port of the modem may not function properly if power is not cycled.
2.5.1.3 Resetting the VT‐MODEM‐4
The modem can be reset to the settings saved by the last &W command, issue the following:
ATX [CR]
If it ever becomes necessary to completely reset the modem including both user profiles to the basic factory default
settings, the following command can be issued:
AT&F&W&W&W1 [CR]
This command string will load the factory defaults into the active configuration (&F) and then save those settings
into both user profile 0 (&W) and user profile 1 (&W1).
Note that after the modem is reset completely to the factory defaults, it will no longer be set to auto-answer, which
is often necessary for the modem to work when connected to a remote device. Use the VT-MODEM Setup Wizard
to adjust these settings appropriately.
2-14
This LED will come ON once a phone line connection has been established, and will remain
on for as long as the connection is maintained.
This LED will come ON when the DTR signal is present regardless the state of the &D
command.
This LED will come ON whenever data is received through the phone line.
This LED will come ON whenever the modem sends data out the phone line.
Normal Indication: This LED will be ON when power is applied to the modem.
DEFAULT INDICATION
Hardware Installation
Maintenance Information
VT-MODEM-4 Hardware Guide
Advertisement
Table of Contents
