If you want to change or add parameters, you need not change the program code. These parameters can be specified in a file called saprfc.ini .
The RFC library will read the saprfc.ini file to find out the connection type and all RFC-specific parameters needed to connect to an SAP system, or to register an RFC server program at an Gateway and wait for RFC calls from any SAP system.
All RFC-specific parameters, both currently known (load balancing, ABAP-debug, RFC with SAPGUI) or becoming available in the future, can be used without changing the RFC programs.
The saprfc.ini file must be in the same directory as the RFC client/server program, or you can define it with full path and file name by the environment variable RFC_INI.
Windows: set RFC_INI = d:\rfctest\saprfc.ini
You can work with the saprfc.ini file only if your RFC SDK was delivered with an Release as of 3.0C. However, the saprfc.ini file is merely a new interface in the RFC library. Therefore, it can work with any R/2 or SAP system.
RFC client programs
To use this new feature, an RFC client program must issue the RfcOpen with RFC_MODE_PARAMETER as mode parameter. The destination must point to an entry of type B , A , 2 , E or R in this saprfc.ini file.
No sideinfo file is necessary when using the new feature.
RFC server programs
To use this new feature, an RFC server program must issue the RfcAccept with -D<destination> as parameter. The destination must point to an entry of type R in the saprfc.ini file.
Restrictions
The parameters ABAP_DEBUG and USE_SAPGUI are only possible if the RFC server system is an SAP system, and the RFC client program does not work with the 16-bit RFC library on Windows. For more details, see Load Balancing .
Possible connection (entry) types
Five connection types are available:
Type R is for RFC server programs or for a client program working with another external program as RFC server program which is already registered at an Gateway.
Type B is recommended for connecting to an SAP system (using Load Balancing).
Type A is only to be used if you want to connect to a specific application server.
Type 2 is for connecting to an R/2 System only.
Type E is for RFC client programs working with another external program as RFC server program.
See RFC Between External Programs for more details about RFC between external programs.