Chapter 4
Installing and Using the FieldPoint Software
FieldPoint FP-1000/1001 User Manual
4-16
©
National Instruments Corporation
For more information about the FieldPoint driver object class and data
members, refer to the National Instruments FieldPoint section of
Chapter 18, Object Class Reference, in your Lookout Reference Manual.
Using the FieldPoint LabVIEW VIs
When you install the FieldPoint software, a library of FieldPoint VIs is
created if LabVIEW has already been installed on your computer. The
FieldPoint VIs (FP Open, FP Get Configuration Info, FP Create Tag, FP
Advise, FP Read, FP Write, and FP Close) directly access the I/O Items
you configured in the FieldPoint Explorer program. In addition, a set of
examples is placed in your
LabVIEW Examples
directory. These
examples are the best way to get familiar with the LabVIEW VIs. The
FieldPoint LabVIEW Help document is in the same program group on
your Windows taskbar as the FieldPoint Explorer program. This help
document explains how to use the FieldPoint VIs.
A simple FieldPoint application to read an I/O Item may only need to
use four of the VIs. To create an example of such an application,
complete the following steps and refer to Figures 4-8 and 4-9. This
application reads the inputs from the I/O Item named All shown in
Figure 4-1.
1.
Use FP Open to open the server. By default, the server opens with
the configuration file you last saved with FieldPoint Explorer.
2.
Use FP Create Tag to create a handle to an I/O Item that you defined
in FieldPoint Explorer. You provide three string names to this VI
to indicate which I/O Item you want access to. These three strings
are the names given to the communications resource, the device,
and the I/O item. Figure 4-7 shows default names as they may
appear when you use the Find Devices button in FieldPoint
Explorer.
3.
Use FP Advise to continuously monitor the I/O Item at the rate
specified in FieldPoint Explorer. (You may also set a new rate with
this VI.) In this example, the while loop executes at this advise rate.
If you used FP Read VI here instead of FP Advise, the loop would
free-run at the fastest rate it could sustain, reading the I/O Item over
the serial port each time the loop ran.
Note:
You should not put more than one FP Advise VI in a loop. All VIs in a loop
execute only once each time a loop runs, and FP Advise VIs only complete
at their advise rate. If you had more than one FP Advise VI in the loop, the
loop (and therefore all of the FP Advise VIs in the loop) would only execute
