Appendix Title
26
TABLE 12-1. Simple AT Commands for SMS
Command
Action Performed
AT+CMGS
Send an SMS from the modem
AT+CMGL
List SMS messages received
AT+CMGR
Read and SMS received
AT+CMGD
Delete an SMS received
Refer to the Intelimax manual for more details on the commands listed and
additional commands that can be used.
The process of sending an SMS can be automated in the datalogger. The
datalogger can also be programmed to read and delete messages in the modem.
Note: Edlog based loggers have limited SMS capabilities. For details on
datalogger programming please refer to the relevant datalogger manual.
12.1
Serial vs TCP/IP
The Intelimax modem is capable of sending and receiving SMS messages in
two modes: Serial Modem mode and PPP WAN mode.
PPP WAN mode is not supported by Campbell Scientific Australia at this time.
12.1.1
Serial Modem Mode
In Serial Modem mode, the modem acts as any other Hayes modem and can
send or receive Circuit Switched Data (CSD) calls. In addition, while CSD is
not active, the modem can send or receive SMS messages.
While both CSD and SMS can be used in this mode, they cannot be used at the
same moment and data logger programs must be constructed to ensure only one
type of communications occurs at one time.
While PPP connection and subsequent TCP/IP communications are technically
possible in this mode, this disables both CSD and SMS for the duration of the
connection. If any form of IP communications are required, use of PPP WAN
mode is recommended.
12.2
Example Serial Program
The following program example sends a single SMS when the temperature of a
thermocouple exceeds 30 degrees Celcius.