National Instruments NI 9512 User Manual - page 36
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Chapter 3
Signal Connections
Figure 3-5.
Drive Enable Circuit Configured for Sinking
Motion I/O Signals
Limit and Home Inputs
The following inputs are available for limit and home functionality on the NI 951x modules:
•
Forward Limit Input
•
Reverse Limit Input
•
Home Input
These inputs are typically connected to limit switches located at physical ends of travel and/or
at a specific home position. When enabled, an active transition on the Forward Limit, Reverse
Limit, or Home input causes motion on the associated axis to stop. The stop mode is
user-configurable in software. Refer to the
NI SoftMotion Module
book of the
LabVIEW Help
for information about the available stop modes.
The Forward Limit, Reverse Limit, and Home inputs are digitally filtered and have
programmable filter frequencies. Active limit and home signals should remain active to prevent
motion from proceeding further into the limit. Pulsed limit signals stop motion, but they do not
prevent further motion in that direction if another move is started.
Forward Limit, Reverse Limit, and Home inputs are not required for basic motion control. These
inputs are part of a system solution for complete motion control.
Caution
National Instruments recommends using limits for personal safety, as well
as to protect the motion system.
Limit and Home Input Circuit
You can use software to enable and disable Forward Limit, Reverse Limit, and Home inputs and
to configure the active state of the signals to on or off. You can also configure the Forward Limit,
Reverse Limit, and Home input circuits for current sinking or sourcing output devices.
V+
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NI 951x
NI 951x V
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inking
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