Chapter 4 NI-DNET Programming Techniques
© National Instruments Corporation 4-11 NI-DNET User Manual
4. Right-click on the ByteOffset terminal and select Create Constant,
then enter 0 as the byte offset.
5. Right-click on the 8[TF] in terminal and select Create Control. In
the front panel control that appears, you can use the button at index 0
to control Run Fwd and the button at index2 to control Fault Reset.
6. Using the NI-DNET palette, place ncConvertForDnetWrite into
your diagram.
7. Wire the DnetData out terminal from the previous Convert into the
DnetData in terminal of this Convert.
8. Right-click on the DnetType terminal and select Create Constant,
then select INT from the enumeration.
9. Right-click on the ByteOffset terminal and select Create Constant,
then enter 2 as the byte offset.
10. Right-click on the I32/I16/I8 in terminal and select Create
Control. You can use the front panel control that appears to change
Speed Reference.
11. Using the NI-DNET palette, place ncWriteDnetIO into your
diagram.
12. Wire the DnetData out terminal from the previous Convert into the
Data terminal of ncWriteDnetIO.
For more information on the ncConvertForDnetWrite and
ncConvertFromDnetRead functions, refer to the NI-DNET Programmer
Reference Manual. For information on LabVIEW data types and their
equivalent DeviceNet data types, refer to Chapter1, NI-DNET Data Types,
in the NI-DNET Programmer Reference Manual.
Accessing I/O Members in C
Since DeviceNet data types are very similar to C language data types,
individual I/O members can be accessed in a straightforward manner. You
can use the standard Clanguage pointer manipulati ons to convert between
C language data types and DeviceNet data types.
The following steps show an example of how standard Clanguage can be
used to access the Basic Speed Control Output Assembly described in the
previous section.
1. Declare an array of 4 bytes, as in the following.
NCTYPE_UINT8OutputAsm[4];