You shoul use this new call instead of all other calls such as RfcOpen, RfcConnect, RfcOpenExt, RfcOpenExtV3 to open an RFC connection.
An RFC client can define all necessary connection data as parameters in this call. It can also use the saprfc.ini file. The client can connect to any R/2, R/3 or external system using this call.
See the saprfc.h header file and the sample program srfctest.c in the RFC-SDKfor more details.
Getting the Message Server Name for Load Balancing
If you use Load Balancing to connect to an R/3 System and there is no information about the host name of the message server (in connect_param of RfcOpenEx or in saprfc.ini), the RFC library will try to get the host name from the sapmsg.ini file customized for the SAPLOGON on Windows.
Usually, these files are installed in the Windows directory. You can also copy them in a directory which is specified by the environment variable RFC_LOGON_INI_PATH.
On non-Windows platforms, you can work with this environment or copy these files to your working directory.
See saprfc.h and sapinfo.c or srfctest.c for more details.
Using 2-byte ISO-language keys
Using the call RfcOpenEx, you can log on to an R/3 System from 4.0 onwards by specifying a 2-byte ISO-language key instead of the 1-byte SAP-language.
You can also this feature to login onto an R/2 or an R/3 release 2.x or 3.x.The RFC library will convert the 2-byte ISO-language key to a 1-byte SAP-language before sending the key to the relevant SAP system.