User's Manual

Chapter 3 Lookout Runtime Menu Commands
Lookout Operator’s Manual 3-10 www.natinst.com
If you set the RTS delay off setting too high, the remote device begins
transmitting its response before the local radio is unkeyed, causing a
communication alarm in Lookout.
Dial-Up Modem Settings
Use the Dial-up serial connection when you use a modem in conjunction
with a switched telephone line (not leased line). You can customize the
dial-up settings for your particular modem and phone line.
The default Dialing prefix settings are based on the Hayes Corporation
AT command set, which is an industry standard for data modems. The
following table explains the Lookout default settings. For additional
commands, refer to your modem operation manual.
When you use an external dial-up modem with Lookout, the DTR line in
your cable between the modem and the computer must be wired straight
through. This line is pin 20 on a 25-pin RS-232 connector and pin 4 on a
9-pin connector. Lookout uses the DTR line to command the modem to
disconnect (hang up) and return to the command mode.
Some factory modems are not configured to respond to the DTR line. After
Lookout first successfully dials out to a remote modem and finishes the
polling cycle, it drops the DTR line, but the modem remains connected. If
the modem does not respond after several seconds of Lookout attempting
to raise and drop the DTR line, Lookout generates an alarm stating that the
modem is not responding. If you receive this alarm message, your modem
is not configured to monitor the DTR line.
Table 3-1.
Dialing Prefix Default Settings
Prefix Description
AT Attention code that must precede all commands
D Dial phone number with these modifiers: P for pulse;
T for tone
E Local echo mode: E for no echo
M Speaker on or off: M for speaker always off
V Verbal or numeric result codes: V for numeric result codes
X Result code and dialing options: X4 waits for dial tone
before dialing, and recognizes busy signal