SMS Connection Interface
To run the following functions the implementation of the SMS Connection Interface library is needed. See the SMS Service Example for one possible implementation. If the device needs hardware handshake and it is not set in the parameters, this can result in data loss.
Modem
This function block should represent the physical device. It must only be started once, before the following ones can be used. To start, the pin for the sim card is needed, if it requires one. Otherwise, this variable can stay empty. Additionally the type of connection is needed. Each one of the following function blocks needs this one to work.
Send SMS
This function block sends a short message to a receiver. Therefore the user has to provide the receiver number and text to send. Perhaps the device cannot read out the service center number from the Sim card. In that case the appropriate error is returned and the user has to provide this number. Also the instance of the modem is required for execution
The execution works just as mentioned above.
Receive SMS
This function block can receive a short message. Always the oldest one, which can be found on the device, is returned. The number, message, time, status and index are returned. The status declares if there was a message on the device or not. The index is necessary to delete a short message. Also the instance of the modem is required for execution.
The execution works just as mentioned above.
Delete SMS
This function block can delete one message in the device. The user must commit the short message in the format, as he received it from the device. Also the instance of the modem is required for execution.
The execution works just as mentioned above.
Visualization
The processes of sending, receiving and deleting can also be done with visualization, but not the initialization of the modem.
After entering the number of the receiver and the message, the button has to be pressed for sending. The lamp next to it shows the current status. A yellow one means that the current process is busy. Green means that the message was send and red that a problem occurred.
The other visualization combines the reading and deleting of a short message. The oldest message of the device is displayed. When no message is available a comment is written. Only the currently displayed message can be deleted. The lamps also show the status as mentioned before.
Used AT-Commands
AT+CMGS: Send Message
AT+CMGR: Read Message
AT+CMGL: List Messages
AT+CMGD: Delete Message
AT+CMGF: Message Format
AT+CPMS: Preferred Message Storage
AT+CSCA: Service Center Address
AT+CMEE: Error Message Format
AT+CREG: Network registration
