Chapter 4
Functional Overview
©
National Instruments Corporation
4-3
NI PCI-7342 Hardware User Manual
Flash Memory
Flash ROM implements the nonvolatile memory on the PCI-7342
controller, which enables the controllers to electrically erase and reprogram
its ROM. Flash memory stores all the embedded firmware, including the
RTOS and DSP code, enabling you to upgrade the onboard firmware
contents in the field for support and new feature enhancement.
Flash memory also allows objects such as programs and data arrays to be
stored in nonvolatile memory. It is possible to save the entire parameter
state of the controller to the flash memory. On the next power cycle, the
controller automatically loads and returns the configuration to these new
saved default values.
Flash ROM also stores the FPGA configuration programs. At power-up, the
FPGAs are booted with these programs, which means that updates to the
FPGA programs can be performed in the field.
Note
A flash memory download utility is included with the NI-Motion software that ships
with the controller.
Axes and Motion Resources
The PCI-7342 controller can control one or two axes of motion. The axes
can be completely independent, simultaneously coordinated, or mapped in
multidimensional groups called vector spaces. You can also synchronize
vector spaces for multi-vector space coordinated motion control.
Axes
An axis consists of a trajectory generator, a PID (for servo axes) or stepper
control block, and at least one output resource—either a DAC output (for
servo axes) or a stepper pulse generator output. Servo axes must have either
an encoder or ADC channel feedback resource. Closed-loop stepper axes
also require a feedback resource, while open-loop stepper axes do not.
Figures 4-1 and 4-2 show these axis configurations.
You can map one or two feedback resources and one or two output
resources to the axis. An axis with its primary output resource mapped to
a stepper output is by definition a stepper axis. An axis with its primary
output resource mapped to a DAC is by definition a servo axis.
