Campbell Com100 Instruction Manual - page 15
COM100 Cellular Phone Package
9
6.1 Datalogger Support Software
Datalogger support software (PC208, PC208E, PC208W) checks the signature
of each block of data as it is received from the datalogger. A poor connection
will result in the retransmission of incorrectly received blocks. If a link is
consistently noisy, use of smaller block sizes may improve throughput. If the
connection is completely broken, the software will write an error message to
the hard disk. The datalogger support software also keeps track of what data
was successfully collected and will attempt to call the datalogger to collect the
remaining data based on the retry schedule in the station file that was created.
If using a relay to switch power to the transceiver, make sure
retries occur at times the transceiver is on
To establish a connection with your remote cellular phone field station requires
setting up your Datalogger Support Software session to call a Campbell Field
Modem and Datalogger. Please refer to your current Datalogger Support
Software Manual for details on setting up a simple phone modem session. The
options listed in our support software do not specifically list the cell phone as
an option. You should choose “ phone modem” or “ hayes modem” when
setting up your station file. As mentioned previously, the COM200/COM210
phone modem used with the COM100 Cellular Phone package supports 300,
1200, 2400, and 4800 baud connections. Campbell Scientific datalogger serial
ports support a 300, 1200, and 9600 baud terminal connection. Additional
commands must be sent to the PC calling modem during the dialing sequence
to allow a 2400 and 4800 baud modem connect speed. Bandwidth limitations
over the Analog Cellular Phone System prevents a reliable modem connection
above 4800 baud.
The command to enable this feature will vary from modem to modem. This
command is added to your initialization string in PC208W. Check your
modem manual to look for a command similar to:
Practical Peripherals Example:
Command
Function
N0
Originate or answer: Handshake only at speed in S37 register
S37=11
Set baud rate to connect at 4800 baud
S7=90
Set modem carrier time-out at 90 seconds
In addition, “ datalogger” extra response times upwards of 3000 msec may be
required as there are variable delays present in the cellular phone system.
When a program is downloaded to a station that switches power
to the transceiver, the datalogger will automatically compile the
program. This will cause all control ports to be reset low. If the
downloaded program does not include the instructions to switch
the transceiver back on, it will be necessary to visit the site and
reprogram the datalogger to set a control port high before
resuming cellular communication.
NOTE
NOTE