SLD_UC RFC connection test issue.

Dear ALL,

I ma moving one r/3 system data in to PO sld using RZ70 ,while pushing the data sld_uc and sld_nuc rfc is failing with below error :

Logon Connection Error Error Details Error when opening an RFC connection Error Details ERROR: Error (Msg DGW 748 not found) Error Details LOCATION: SAP-Server Error Details COMPONENT: CPIC Error Details COUNTER: 19 Error Details MODULE: Error Details LINE: Error Details RETURN CODE: 748 Error Details SUBRC: 0 Error Details RELEASE: 721 Error Details TIME: Sun Feb 08 10:23:32 2015 Error Details VERSION:

and below is the log from work directory:

**** Versions SAP-REL 721,0,300 RFC-VER U 3 1498740 MT-SL

======> CPIC-CALL: 'ThSAPOCMINIT' : cmRc=19 thRc=748

Error (Msg DGW 748 not found)

ABAP Programm: RSRFCPIN (Transaction: SM59)

Destination: SLD_UC (Handle: 2, DtConId: 2560AFE4264BF1B7AB970050569B253B, DtConCnt: 0, ConvId: ,)

EPP RootContextId: 0050569B253B1EE4ABEA1E3C1EA48B97, ConnectionId: 00000000000000000000000000000000, ConnectionCnt: 0

EPP TransactionId: 2560AFE4264BF1B4AB970050569B253B

Error RFCIO_ERROR_SYSERROR in abrfcpic.c : 1730

CPIC-CALL: 'ThSAPOCMINIT' : cmRc=19 thRc=748

Error (Msg DGW 748 not found)

DEST =SLD_UC

HOST =%%RFCSERVER%%

PROG =SLD_UC

GWHOST =SAPPLA

GWSERV =3301

Kindly please advise how to resolve the issue