National Instruments 7344 Series, User Manual

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Chapter 5 Signal Connections
7344/7334 Hardware User Manual 5-10 ni.com
edge. You can also use a trigger input as a latching general-purpose
digital input by simply ignoring the captured position.
• Shutdown Input — The shutdown input signal, when enabled in
software, can be used to kill all motion by asserting the controller
inhibits, setting the analog outputs to 0 V, and stopping any stepper
pulse generation. To activate shutdown, the signal must transition from
a low to high state (rising edge).
• Breakpoint Output <1..4> — A breakpoint output can be programmed
to transition when the associated encoder value equals the breakpoint
position. You can use a breakpoint output to directly control actuators
or as a trigger to synchronize data acquisition or other functions in the
motion control system.
You can program breakpoints as either absolute , modulo , or relative
position. Breakpoint outputs can be preset to a known state so that the
transition when the breakpoint occurs can be low to high, high to low,
or toggle.
The breakpoint outputs are driven by open-collector TTL buffers that
feature 64 mA sink current capability and built in 3.3 k
Ω pull-up
resistors to +5 V.
You can directly set and reset breakpoint outputs so you can use them
as general-purpose digital outputs.
Wiring Concerns
Caution Keep trigger input, shutdown input, and breakpoint output signals and their
ground connections wired separately from the motor driver/amplifier signal and encoder
signal connections. Wiring these signals near each other can cause faulty operation.
Excessive input voltages can cause erroneous operation and/or component failure.