Direct Modem Connection
ClockWatch can call the NIST directly over the phone lines
using an external or internal modem. Instead of connecting to a timeserver over the
Internet, the NIST is dialed directly with your computer's modem, the time signal is synchronized,
and the time setting is made.
the direct modem connection option when Internet service is
unavailable or otherwise undesirable. Direct
modem connection is an option with ClockWatch Pro and ClockWatch Server,
but is not
available in ClockWatch Client or ClockWatch Basic.
Steps to use the direct
Have a modem (internal or external) connected to a serial port. The modem must
first be installed under Windows.
Select the communications port used for the modem on the direct modem connection form.
Check the "direct modem connection" server type.
Modify the phone number or dialing prefix if you cant dial long distance numbers
directly (or you happen to be in the same area code as the NIST).
Test the connection by pressing the "Set Time" button on the main form.
If the modem has a speaker, listen for the modem to go off hook, get a dial tone, and
dial the number. Then listen for the NIST modem to answer the call and
establish a connection between the two modems.
Direct Modem Connection Configuration Options
Serial Port Settings
Select the COM port of the modem you are dialing out with. This is the
number of the serial port where the internal or external modem is attached.
Enter the baud rate as a number. The modems at the NIST handle normal modem
speeds from 300 to 9600 baud.
Modem Command Strings
Enter the modem command string for initializing the
modem. This string is used to prepare the modem to call out and precedes the dialing of
the phone number. The direct connection procedure in ClockWatch expects that the modem
respond with OK after each modem command is issued.
Enter the modem command string to dial out.
Enter the modem command string to hang-up the modem after
communication is finished.
Hint: You can use a terminal program such as HyperTerminal (a standard Windows
accessory) to verify the modem is installed properly and the commands sent to the modem
are correct. Configure HyperTerminal to open the same com port the modem is using (but not
the modem itself) and type in the same command strings that are used to see if the modem
Enter the dialing prefix (if any) required to dial out.
This digit is dialed before the NIST phone number. If you include commas
the string, then the dialing will pause a period of time (about one
second) for each comma in the string.
NIST Phone Number
Enter the phone number of the NIST ACTS modem. The
default value calls the NIST in Boulder, Colorado, USA.
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