User manual

Using with Campbell Scientific Dataloggers

5.6 Sending configuration commands to the modem

It is often advisable to reset the modem at regular intervals or send other

configuration commands to the modem, for instance to enable very low power

states between calls. When using the loggers IP Stack, this can be done within the

datalogger program by opening the serial port to which the modem is connected

and sending out commands using the serialout command. To allow another PPP

connection the program must close the serial port using serialclose otherwise the

PPP connection will be permanently blocked.

When using the Modem IP stack configuration commands are not normally sent

from the datalogger.

6. Installation of the COM110A modem

6.1 Configuring and Fitting the SIM

Before the COM110A modem can be used or tested, it must be fitted with a ‘SIM’

card (Subscriber Identification Modem) that enables it for use on a specific

cellular telephone network in a particular frequency band..

If possible, ensure that the SIM is configured so that it does not require a Personal

Identification Number (PIN) security code to be entered after the modem is

powered up. The PIN can most easily be disabled by inserting it into a separate,

hand-held standard GSM phone and following the instructions contained in the

phone manual. If a separate phone is not available, please contact Campbell

Scientific for details of how to disable the PIN code for use with the COM110A. If

this is not possible, or if your airtime provider only allows operation with a PIN

enabled, please refer to Appendix A.

Some SIM suppliers send the SIM with the PIN enabled and set to a

default PIN number. Check the documentation that came with your

SIM.

The SIM card is installed in the COM110A modem in the slot at the aerial end of

the case. Before installing the SIM make sure power is disconnected from the

modem. The SIM is installed in a small tray that has to be ejected by pushing in

the small green button which is to the rights of the slot holding the tray. Use a pen

or similar to push the button inwards. Insert the SIM with card with the gold

contact side of the card facing upwards in the tray. Ensure the cut-out of one

corner of the card is orientated to match the recess in the tray so the SIM sits flat

in the tray. Push the tray back into the slot until fully in then, with the aerial

connected, power on the modem and check if the LED starts flashing within a

minute or so to indicate successful registration on the network.

6.2 Connection to a Datalogger

The COM110A modem can either be connected directly to the RS232 port of the

datalogger, if it has one, using the RS232 cable provided as part of the CS-

GSM/GPRS232 kit or to the CS I/O port of dataloggers that have this port, using

an SC-WMI or SC105.

If your datalogger has both an RS232 and CS I/O port you may still wish to use an

interface as it frees the RS232 port allowing a local PC to be connected to be used

or for connection to a sensor.

NOTE