How to create RFC function module and how to call this function module

Question

Hi,
i want to know step for creating RFC function module and then How to  use this function module from some other sap system.
Thnaks,
jigar

Answer 1

Jigar,
To implement a remote function module in ABAP, perform the following steps:
Register the module as remotely callable in the RFC server system.
In the function module Administration screen (transaction code SE37), set the field Can be called via REMOTE CALL. Registering a module as remote causes an RFC stub to be generated for it.
Write the code for the function module.
Create the destinations.....................
Displaying, Maintaining and Testing Destinations
To display, create or modify destinations, choose Tools ® Administration ® Administration ® Network ® RFC destinations or enter transaction code SM59.
Remote Destinations are stored in table RFCDES. The RFCDES table describes logical destinations for remote function calls.
It is not possible to maintain the RFCDES table directly.
You can also access logical destinations via the Implementation Guide (IMG) by choosing Tools ® AcceleratedSAP ® Customizing ® Execute Project ® SAP Reference IMG.
In the Implementation Guide, expand the following hierarchy structure:
Basis
Application Link Enabling (ALE)
Sending and Receiving Systems
Systems in Network
Define Target Systems for RFC Calls
Displaying Destinations
The initial screen for this transaction displays a tree:
Different connection types (i.e. partner systems or programs) are possible. For further information, see Types of Destinations.
To display all information for a given destination, double-click it, or place the cursor on it and press F2 .
To search for a destination, press the Find button and specify your selection. You get a list of all entries matching your selection. Place the cursor on the one you want, and press F2 or simply double-click the destination. All information for the given entry appears.
Creating Destinations
On the destinations overview screen (transaction code SM59), the connection types and all existing destinations are displayed in a tree structure.
All available connection types are explained in Types of Destinations.
To create a new RFC destination, press the Create button. A new screen is displayed with empty fields for you to fill in.
If you want to create a new destination
As you create a remote destination, you can specify a particular application server or a group of servers for a balanced distribution of system load.
For details of the destination parameters, see Entering Destination Parameters.
Changing Existing Destinations
On the destinations overview screen (transaction code SM59), the connection types and all existing destinations are displayed in a tree structure.
You can display all information for a given destination by double-clicking it or pressing F2 on it.
To change an existing destination, double-click it, or place the cursor on it and press the Change button.
For details of the destination parameters, see Entering Destination Parameters.
Testing Destinations
To test a destination, choose the appropriate function from the Test menu.
Connection (also available via the Test connection pushbutton)
Authorization (checks logon data)
Local network (provides a list of application servers)
You can use the CALL FUNCTION statement to call remote functions, just as you would call local function modules. However, you must include an additional DESTINATION clause to define where the function should run:
CALL FUNCTION RemoteFunction
DESTINATION Dest
EXPORTING
f1 =...
f2 =...
IMPORTING
f3 =...
TABLES
t1 =...
EXCEPTIONS......
The field Dest can be either a literal or a variable: its value is a logical destination (for example, "hw1071_53") known to the local SAP System. Logical destinations are defined in the RFCDES table (or the TRFCD table in R/2 Systems) via transaction sm59 or the following menu path: Tools ® Administration, Administration ® Network ® RFC destinations. You can also access logical destinations via the Implementation Guide (IMG) by choosing Tools ® Customizing ® Enterprise IMG. In the Implementation Guide, you can then choose Cross-application components ® ALE ® Communication ® Define RFC destination.
The remote function call concept, for example, allows you to access a function module in an R/2 System from an ABAP program in an R/3 System. If you want to read a customer record from your R/2 System’s database, create a remotely callable function module in the R/2 environment which retrieves customer records. Call this function from your R/3 System using a remote function call and listing the destination for the target R/2 System:
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