RFC Trigger
Connected SAP® systems use the RFC trigger to initiate data transfers in the OPC Router. To do this, a corresponding entry must be created in transaction SM59 on the SAP® side.
Dialog Overview
The screenshot shows the selection of the SAP® connection as well as the configuration of the program ID, gateway service, function, and parameters.
Configuration
| Property | Description |
|---|---|
| SAP Connection | All SAP® connections created in the Plug-ins section are available for selection here. If the desired connection does not yet exist, you can make it available in the Plug-ins section as an SAP® connection. |
| Program ID | Program ID used to call the destination on the SAP® system; identical to the program ID in transaction SM59. |
| Gateway Service | RFC protocol: Enter the gateway, for example sapgw00 (SAP Gateway 0). NetWeaver RFC protocol: Specify the port (3300 + Id for Basic authentication, 4800 + Id for SNC authentication). |
| Function | Function defined in the SAP® system that triggers this trigger. |
| Timeout | Time period after which the OPC Router sends a timeout message to the SAP® system if the task is still in progress. |
| Output | Select this field if you want to receive output as JSON. |
| Input (Input tab) | Parameters that the calling SAP® system passes to the OPC Router when triggering the function (import parameters of the function module). |
| Output (Output tab) | Parameters that the OPC Router returns to the calling SAP® system after the connection is established (export parameters of the function module). |
| Tables (Tables tab) | Table parameters used in both directions—they can pass data to the call and return (modified) data to SAP®. |
| Copy JSON Format | Copies a JSON document to the clipboard whose structure corresponds to the function call. |
Input, Output, and Tables
An RFC function module has a fixed interface consisting of parameters. With the RFC trigger, the OPC Router assumes the role of the called module—you therefore define its interface using three tabs:
- Input: Values that the SAP® system passes to the OPC Router when the function is called. These values are then available in the connection.
- Output: Values that the OPC Router returns to the SAP® system after the connection ends. These values are populated in the connection.
- Tables: Tables (multi-line data structures) that can be used in both directions.
In each tab, create the required parameters by assigning a name and selecting the data type. In addition to simple types, STRUCTURE (a structure with multiple fields) and ITAB (an internal table) are also supported. For these types, use “Edit” to define the individual fields; nesting is not permitted.
For CHAR and NUM fields, specify the expected length via “Edit.” The default length is 0; if it has not been changed, a corresponding message appears when you close the dialog.
Calling a nonexistent function module will inevitably result in the server being unregistered in the SAP® Gateway. The registration can no longer be used and must be performed again, which in ERP-Connect results in a server restart.
Functions that have been registered with the NetWeaver Library cannot be deleted. This applies to the entire process, across all SAP® systems and RFC servers. Therefore, you cannot subsequently change the name or type of the import/export/tables parameters of a function module called via an RFC server, nor can you alter the existence of the function module itself. Do not make any changes while the OPC Router service is running. If changes are made, the function module must always be republished in its entirety.
Return Parameter
When the SAP® system calls the function module, the OPC Router executes the corresponding connection and then returns a result to the calling SAP® system. The SAP® system uses the return parameter TRANSFER_OK to determine whether the transfer was successful:
| Name | Description |
|---|---|
| TRANSFER_OK | 1 = OK: Successful transfer of the connection. 2 = Aborted: The transfer was aborted by a transfer object, for example, if a table for a database transfer object contained no data. 3 = Error: An error occurred during the transfer. The request must be resent later and must not be marked as completed by the connected system. |
Register the function name in ALL CAPS (for example, Z_TRIGGER): SAP® passes function module names in uppercase, and the OPC Router matches them character-for-character—a lowercase registration will not be found. The program ID is also evaluated on a character-by-character basis (case-sensitive) and must match exactly the entry in the SAP® transaction SM59; uppercase is common and recommended, but not mandatory. The call on the SAP® side is:
Call function '<funktionsname>' destination '<sap-destination>'.
The combination of host (SAP connection), gateway, and program ID must be unique. The program ID itself can be used multiple times—but only with different gateways/hosts.
Example
Settings for the RFC trigger:
| Property | Configuration |
|---|---|
| SAP connection | <sap-anbindung>, through which the relevant function is accessed. |
| Program ID | INRAYTRIGGER |
| Gateway service | Gateway service of the SAP® system, for example 3302 |
| Function | TRIGGERFUNKTION |
Corresponding SAP® settings, SM59:
The program ID INRAYTRIGGER was created in the SAP® transaction SM59.
| Property | Configuration |
|---|---|
| Destination | OPCROUTER |
| Connection Type | T TCP/IP |
| Activation Type | Registered Server Program |
| Program ID | INRAYTRIGGER |
| Gateway Host | (no entry!) |
| Gateway Service | (no entry!) |
The data transfer is actively triggered by the SAP® system through a synchronous function call within a program, function module, or dialog in SAP®:
Call function 'TRIGGERFUNKTION' destination 'OPCROUTER'.
```</sap-anbindung></sap-destination></funktionsname>