Agilent Technologies E5071C Manual page 1065

E5071C
'version 2.0 (2*256 + 0) = 512
'Get WinSock version
Sheets("Sheet1").Select
Range("C2").Select
version = ActiveCell.FormulaR1C1
'Initialize Winsock DLL
x = WSAStartup(version, StartUpInfo)
End Sub
Socket Creation and Connection
The procedure for Socket Creation and Connection is OpenSocket.
OpenSocket makes a connection to an instrument associated with the IP
address specified with the input parameter Hostname. It uses a socket of
the port specified with the input parameter PortNumber. Each functional
part of OpenSocket is described below.
In (1), the inet_aadr function of WinSock API is used to convert an IP
address delimited by "." to an Internet address.
In (2), a new socket is created with the socket function of WinSock API
and its socket descriptor is obtained. If an error occurs, the control returns
to the main program with a message. The socket function takes an address
family (input), a socket type (input), and a protocol number (input) as its
parameters.
In (3), the socket address is specified. Note that htons, which is used for
specifying the port number, is a function of WinSock API. This function
converts a 2-byte integer from the Windows byte order (little endian) to
the network byte order (big endian).
In (4), a connection to the E5071C is made by using the connect function
of WinSock API. If an error occurs, the control returns to the main program
with a message. The connect function takes a socket descriptor (input), a
socket address (input), and the size of the socket address (input) as its
parameters.
OpenSocket
Function OpenSocket(ByVal Hostname As String, ByVal PortNumber As Intege r) As Integer
Dim I_SocketAddress As sockaddr_in
Dim ipAddress As Long
ipAddress = inet_addr(Hostname) '...........(1)
1292