CipherLab 9400 Series User Manual page 183

Return Value If successful, it returns 1.
Otherwise, it returns 0.
Remarks Please make sure the GPRS power is turned on before calling this function.
See Also SetGPRSPower
Call GetErrorCode() to find the error condition encountered:
33 ERROR_MACHINE_NOT_SUPPORTED
It may return error codes defined by Microsoft. Please refer to
http://msdn.microsoft.com/en-us/library/bb530704(VS.85).aspx.
Chapter 3 System API
175