Measurement Computing Net232 - Manual (Page 11)

Net232 User’s Guide, 1037-0901, rev 2.0 11
Ethernet API Reference
Overview
Users can write their own programs with an ethernet API. The API is provided by two software files:
NPCI_WIN.DLL for 16-bit windows developers, and NPCI_W3V.DLL for 32-bit windows developers.
The only system requirement is that the Windows TCP/IP protocol be loaded and configured.
With a mechanism called session handles, the API can simultaneously handle multiple Net232 units. All functions
rely on the session handle to keep track of the Net232 selected for communication.
A typical session with a Net232 consists of the following basic parts:
• Initialization - Initialization requires several functions to be called in appropriate order. These functions include:
nSWInit
, nSessionBegin, nIOLock and nSERIALConfigure.
• Actual communications (during the session) - Communication functions include nSerialReceive and
nSerialSend .
• De-initialization – De-initialization is for ending a session, and uses the functions: NSessionEnd and NSWDeinit.
Detailed descriptions of each function are covered in the following section. Examples programs are also included on
the distribution disk.
Functions
nSWInit
Function: int nSwInit(void);
Parameters: None
Returns: 0 if successful, error code if not.
Description: This function is used to allocate system resources prior to beginning a session. This function must be
called before any others.
Example:
ErrVal = nSWInit ();
nSessionBegin
Function: int nSessionBegin (short adapter, char FAR *local, char FAR *remote,
unsigned long flags, unsigned long reserved, long FAR *session);
Parameters:
Short adapter Always a 0.
Char FAR * local Always a null string.
Char FAR * remote A null terminated string, which contains the IP address of the Net232.
Unsigned long flags Always zero
Unsigned long reserved Always zero
Long FAR * session A variable used to receive the session handle.
Returns: 0 if successful, error code if not.
Description: This function is used to establish a session with a specific Net232. If a successful connection is made,
then a session handle is assigned and placed in the session argument. Since each session is unique, it is
possible to have multiple sessions active at any given time.
Example:
ErrVal = nSessionBegin(0,”\0”,”192.0.0.1\0”,0,0.session);