Instruction manual
PC208W, Version 3.0, Instruction Manual B-1
APPENDIX B. MODEMS
B.1 PHONE MODEMS
After adding a new Phone Modem to the Device
Map, you can click on the Hardware Tab | Edit
Modem Strings to set up specific parameters
related to the modem. Information for each
modem is stored in the WMODEM3.INI file in
the PC208W directory. This file is updated
each time a field in the Hardware page is
changed.
The available fields on this set up page are:
modem pick list, modem name, modem reset
string, and modem initialization string. Each of
these is explained below.
Modem Pick List
Common modems are available in the Modem
Pick List. When a modem is chosen from the
Pick List, the remaining parameter fields are
automatically filled in with default values for that
particular modem. These default values can be
changed by editing the desired field.
If the modem you are using is not listed, you
can choose <default modem> (or create a new
modemsee Modem Name below) and edit the
remaining parameters according to your
modem’s specifications.
Modem Name
A new modem can be created by editing an
existing modem name or entering a new name.
You can also remove an entry from the Modem
Pick List by deleting its name from this field and
then selecting a new modem as its
replacement.
Modem Reset String
This string is sent to return the modem to a
known state. This state is such that the modem
is off-line and ready to receive dialing
commands. Usually the string will set the
modem back to factory defaults, but a string to
use settings stored in non-volatile memory can
be used once those settings are stored. Your
modem user manual should provide the
command to reset the modem to its factory
defaults (often this is &F0, &F1, etc.)
Modem Initialization String
This string is used to prepare the modem for
use with the dataloggers and Campbell
Scientific field or voice modems. Typically,
these commands enable flow control,
compression, verbal result codes, and error
checking.
B.2 GENERIC MODEM DIALING
STRINGS
Generic modem is specified for modems
requiring special dialing. Generic modem
dialing has the following characteristics:
• No automatic reset string (like “ATZ”) is
sent.
• Actual commands sent are specified by the
user.
• Dialing can be paused for specified delays
or responses.
The command string or “phone number” is
formulated as follows:
“xx”The actual text to be sent is enclosed in
quotes. Control characters can be sent to the
modem using the ^ character. For example, ^m
would produce a <Ctrl>M, which is a carriage
return character. Specify ^^ to send the ^
character, and ^~ or ^> to specify a <Ctrl>^.
PC208W will wait for the echo of each character
sent. If no echo is received within the duration
specified in the Extra Response Time (msec)
parameter, PC208W continues with the next
character.
T“xx”Similar to above, except the text
enclosed in quotes is sent without waiting for an
echo.
Delays and responses are implemented with the
following characters (not enclosed in quotes):
DnDelay command. This forces the
preceding portion of the command string to be
sent, then delays for n milliseconds. Characters
received during a delay are accepted and
discarded.