External device connection: RFC Server?

Question

Hello to all,
i'm new here.
I'm facing a new problem i never met before.
I'm on a 4.7 enviroment and i have to interface sap with an external device.
The producers of external device, release an executable file that makes (but i don't kwnow how) the communication from the device and sap.
The only things that i had to do was (following the device documentation):
1. Create a tcp/ip remote destination that point to one external executable (es: Z_EXT_DEVICE --> c:\device\device2sap.exe) (if i double-click on it, it don't do anything) 
2. Setup in the external setup device program (setupdevice.exe), the name of the RFC destination (Z_EXT_DEVICE), the sapgateway address (sapgw00) and the sap host address (ex 10.2.4.XX)
(Note that i don't have to specify sap usr/pwd for the connection in any step).
3. Call a simple function module in SAP system in this way:
CALL FUNCTION 'Z_RFC_DATA' DESTINATION 'Z_EXT_DEVICE'
    EXPORTING
      header        = szheader
      data          = szdata
      status        = '0'
      data_len      = szvalue
    IMPORTING
      system           = szretsystem
      code             = szretcode
      ret_text         = szrettext
      header           = szanswerheader
      len_data         = szlendata
      bct_status       = szstatus
      bct_data         = szanswerdata
    EXCEPTIONS
      communication_failure  = 1
      system_failure         = 2
      OTHERS                 = 3.
The code of the function module is empty :
FUNCTION Z_RFC_BCT.
""Lokale Schnittstelle:
*"  IMPORTING
*"     VALUE(HEADER) LIKE  BAPIRET2-MESSAGE
*"     VALUE(DATA) LIKE  BAPIRET2-MESSAGE
*"     VALUE(STATUS) LIKE  BAPIRET2-MESSAGE
*"     VALUE(DATA_LEN) LIKE  BAPIRET2-MESSAGE
*"  EXPORTING
*"     VALUE(SYSTEM) LIKE  BAPIRET2-MESSAGE
*"     VALUE(CODE) LIKE  BAPIRET2-MESSAGE
*"     VALUE(RET_TEXT) LIKE  BAPIRET2-MESSAGE
*"     VALUE(HEADER) LIKE  BAPIRET2-MESSAGE
*"     VALUE(DATA) LIKE  BAPIRET2-MESSAGE
*"     VALUE(LEN_DATA) LIKE  BAPIRET2-MESSAGE
*"     VALUE(STATUS) LIKE  BAPIRET2-MESSAGE
*"  EXCEPTIONS
*"      COMMUNICATION_FAILURE
*"      SYSTEM_FAILURE
ENDFUNCTION.
After the call of the function module in sap system, magically the importing variables are filled all by values read from the external device. At this point I'd like to ask u some questions :
1. I think that external device program (device2sap.exe) is an RFC server program. Is it right ??
2. How the connection from external executable and sap works if i don't specify usr/pwd in any configuration file? The device    infact, work with every sap (if u execute the three sinple step wrote before)
3. I'd like write a server like that for a different external device. In the old release of sap (4.0,4.5) there was a sap tools (in function module editor SE37) that permitted (starting from a function module), to generate a client or server external program (in C or VB). In 4.7 this functionality is missing. Is there other sap tools that permitt to do the same thing or this functionality is completly lost?? In the second case, do u have some hits that could help me in this step??
4. I'd like to have some documentation about the server program and communication methos between external RFC server program and Sap. Where i can find some good documents that could help me in that task ??
5. I heard about DCOM connector. Where i can find some good documentations that explain how is it , how it works and if it could solve my problem ?
Thanks a lot in advance.
Andrea

Answer 1

Hi, I'm sure the device2sap.exe is developed by a Connector Tools. E.G. .Net Connector, Jco and so on.
So reply your question as following:
1. Yes, in the external application side, it can simulate a RFC server for the SAP to call, just like call to another R3 server.
2. No need on use/pw. it is not DataBase connection, just a RFC connection. The key feature only need is the IP. And you should configure the RFC destination using IP. RFC is a FM call protocol, not to access a DB.
3. Using the Connector tools I mentioned in the former reply. And you can navigate in the .Net Tech Forum in SDN.
4. The guide of Connector Development can be get from SDN, and some sample code will be copy in the install directory, after you installed it.
5. DCOM is the tech used in the former Connector version SAP DCOM conncetor. Now, as the windows is into the Dotnet Time, recommand you to use DotNet Connector.
That's all.   hope it will be helpful