Inbound: Triggering the SAP System

In this section, the SAP System is made known to the upstream system (startrfc program parameters). Conversely, the upstream system is made known to the SAP System via the port definition .


You require the startrfc program from the RFC library.


Enter the command with the logon and function module parameters specified below. For example, the command line under Unix could begin as follows:

startrfc -3 -d C11 -u EDIUSER ...

The parameter sequence is not important.

Logon parameters


Value (Example)



Logon to the SAP system using RFC



SAP system ID. This is displayed in the system bar, for example.



SAP user
Enter the name in upper case letters.

For security reasons, you should use a CPI-C user, as this user type cannot be used in a dialog.

The user requires all of the necessary authorizations.



User password.

Enter the password in upper case letters.



SAP client (default: 000)
as contained in the MANDT field in the control record.



SAP system language (default: EN)



Application server (message server): Call transaction SM51. The first part of the server name field (separated by underscores) stands for the application server. This character string is case-sensitive.



Two-digit system ID (TCP/IP service): Call transaction SM51. The third part of the server name field (separated by underscores) stands for the system ID.



Gateway host:

1. Call transaction SE38.

2. Enter the report name RSPARAM.

3. Select Execute and do not select the field Display also unsubstituted (the system variable values are then displayed)

4. Select Find (CTRL-F)

5. Enter rdisp/sna_g and confirm your entry

6. The name of the gateway host is displayed in the line rdisp/sna_gateway (you may have to scroll to the right)

This character string is case-sensitive.



Gateway service as in /etc/services :

1.-5. Repeat steps 1-5 for the gateway host (parameter -g)

6. The name of the gateway service is displayed in the line rdisp/sna_gw_service (you may have to scroll to the right)

This character string is case-sensitive.


Writes the log data to the file dev_rfc in the current directory.

Function module parameters for inbound IDocs


Value (Example)




Only this function module reads IDoc files.



EXT/in/<file name>

Directory and name of the file which contains the IDoc (max.100 characters)



Logical name of the external system as defined in the port definition (max. 10 characters)


You have notified the upstream system of the SAP function module to be called and the parameters (file and directory) to be used. Store the name of the upstream system (EXT parameter value in the above table) in the Port definition (section "inbound"), so that the SAP System recognizes the name and accepts the IDocs (see Port Type File: Maintaining Port Definition inbound).

Once you have maintained the port definition, the file transfers are triggered in the following sequence (see the graphic below):


       1.      The upstream external system writes the data to a sequential file in IDoc format.

       2.      The external system starts the SAP System with the rfcexec program.

       3.      The name and directory of the file (as well as the port) are transferred to the SAP System as startrfc parameters.

       4.      The SAP System reads the inbound file and then deletes it. It does not return any status information to the external system.