AuthenticationServiceSoap = interface(IInvokable)
 ['{...}']
   function  AutoLogin: Boolean; stdcall;
   function  Login(const username: WideString; const password: WideString; const clientVersion: WideString): UserInfo; stdcall;
   function  Logout: Boolean; stdcall;
 end;

function GetAuthenticationServiceSoap(UseWSDL: Boolean=System.False; Addr: string=''; HTTPRIO: THTTPRIO = nil): AuthenticationServiceSoap;

implementation

function GetAuthenticationServiceSoap(UseWSDL: Boolean; Addr: string; HTTPRIO: THTTPRIO): AuthenticationServiceSoap;
const
 defWSDL = 'D:\xml\ASV.Services.AuthenticationService.xml';
 defURL  = 'http://.../csp/asv/ASV.Services.AuthenticationService.cls';
 defSvc  = 'AuthenticationService';
 defPrt  = 'AuthenticationServiceSoap';
var
 RIO: THTTPRIO;
begin
 Result := nil;
 if (Addr = '') then
 begin
   if UseWSDL then
     Addr := defWSDL
   else
     Addr := defURL;
 end;
 if HTTPRIO = nil then
   RIO := THTTPRIO.Create(nil)
 else
   RIO := HTTPRIO;
 try
   Result := (RIO as AuthenticationServiceSoap);
   if UseWSDL then
   begin
     RIO.WSDLLocation := Addr;
     RIO.Service := defSvc;
     RIO.Port := defPrt;
   end else
     RIO.URL := Addr;
 finally
   if (Result = nil) and (HTTPRIO = nil) then
     RIO.Free;
 end;
end;

var
    varUserInfo: UserInfo;
...
varUserInfo := GetAuthenticationServiceSoap().Login('<username>','<pwd>','1.1');
...