Chapter 5 Accessing cFP-20xx Channels from PC Applications
cFP-20xx and cFP-BP-x User Manual 5-2 ni.com
to call C functions that directly access I/O items you configured in MAX.
In addition, a set of sample projects is placed in your
LabWindows/CVI
Samples
directory. Using these examples is the best way to get familiar
with these functions. The FieldPoint LabWindows/CVI Interface Help
describes each function in the instrument driver with a description of the
C syntax, a description of each parameter, and a list of possible error codes.
Note FieldPoint CVI Interface Compatibility Modes—The FieldPoint software ships
with object (
.obj) files to support the different compiler compatibility modes that
LabWindows/CVI supports (Microsoft Visual C/C++, and Borland). When the FieldPoint
software is installed, the
.obj file corresponding to the configured compatibility mode is
installed.
FieldPoint OPC Server and the cFP-20xx
The FieldPoint OPC server conforms to the OPC Data Access 2.0 standard.
OPC (OLE for Process Control) is an industry-standard device interface
specification that provides interoperability between field devices such as
FieldPoint and application software packages. The FieldPoint OPC server
imports I/O items that you configured in MAX and makes them available
as OPC items to any OPC client. Therefore, if two computers are
networked together, it is possible for an OPC client on one computer to
access FieldPoint hardware connected to the OPC server on another
computer.
OPC clients differ in the features they offer and in their presentation of the
OPC interface for the FieldPoint OPC server. Refer to the documentation
on using the OPC client features of your application for detailed
instructions on how to access an OPC server. However, the basic steps
involved are similar for most OPC client applications.
Complete the following steps to use the FieldPoint OPC server:
1. Launch your OPC client.
2. Open the FieldPoint OPC server,
National
Instruments.OPCFieldPoint
, from the OPC client.
This server was registered with Windows when you installed the
FieldPoint software. OPC clients should be able to show you a list
of available registered servers, but you may have to type this name
in yourself. The OPC client may automatically connect to the server
when you select it, but if you are given the option to connect to the
FieldPoint OPC server, you should do so.
3. Create a group.