Fault Finding
There are a number of reasons why an SMS may fail to be sent with the SendSMS function block or via the SMS COM server:
- no connection to the GSM modem
- the use of an unsupported GSM modem
- incorrect phone number
- incorrect GSM network
- PIN required (the SIM card must not be protected by a PIN)
- serial terminal not initialized (call KL6Init)
- incorrect call of the ADS service
A variety of tools are available to look for these errors:
Using the Log File
Keeping records in a log file can be activated with the TwinCAT SMS Server Configurator. Once this has been done, all the messages sent and the errors are written into the TcSmsSrvCfg.xml file. The file can be found in the TwinCAT installation directory.
NT Event Log
Errors when sending messages are also always recorded in the NT Event Log. The Event Log can be opened through the TwinCAT icon on the task bar.
ADS Error Messages
If the call to an ADS Function fails, the error is coded in the function's return value. A list of these error codes can be found under ADS Return Codes.
Configuration of the terminal
The serial terminal can be configured in different ways. Terminals that have been differently configured, have to some extent a different representation in the process image (3 byte /5 byte terminals, advanced/standard). Please note that the ‘Serial Communication’ library must match the configuration of the terminal. See also the documentation for the KL6xxx and the ComLib documentation:
It is also important to match the transmission speed of the terminal to the modem used.
Sending a Test SMS
A test SMS can easily be sent with the Visual Basic example program, to find out whether an error lies with the ADS call or in the configuration of the SMS Server.
Sending a test SMS with a mobile phone
Enter number.
Network Selection with the Westermo GS-01
GS-01 has a number of variations for the various networks in Europe and in the USA. The lamp on the front of the modem indicates whether a network is available. The lamp flashes if the modem is connected to a network. If the lamp is continuously illuminated, the fault finding section should be consulted in the Westermo manual.