Ni Softmotion Engine To Fpga Communication - National Instruments 9501 C Series Getting Started

Table 1. Stepper Drive (Getting Started) UDV Descriptions (Continued)
UDV Name
Axis 1.Status Register
Axis 1.Steps Generated

NI SoftMotion Engine to FPGA Communication

Each User-Defined Variable communicates information between the NI SoftMotion Engine and
the LabVIEW FPGA Module. These UDVs are used directly with the Drive Interface FPGA VIs
in specific loops on the block diagram. Complete the following steps to open the FPGA VI and
display the block diagram.
1. Expand the FPGA Target item in the LabVIEW Project Explorer window.
2. Double-click the Stepper Drive (Getting Started) - FPGA.vi item to open the VI.
3. Select Window»Show Block Diagram to open the FPGA VI block diagram.
Fault Monitoring Loop
The Fault Monitoring loop sends fault information, including user-defined faults, to the
NI SoftMotion engine and sends the state machine implemented in the Control Status Loop into
a fault state. Figure 7 shows the Fault Monitoring Loop from the Stepper Drive (Getting Started)
example.
Figure 7. Stepper Drive (Getting Started) Fault Monitoring Loop
1 Fault Code Array
Getting Started with NI 9501 Modules and NI SoftMotion | © National Instruments | 11
Contains information used to report status and operation
mode information from the device to the system.
Returns the current step count of the stepper generator
taking into account the direction. This value is based on
actual steps generated, not feedback position, and may not
exactly match the feedback position.
2 Write Fault Drive Interface VI
Description
1 2