NI PCI-7390, Руководство пользователя

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Chapter 4 Signal Connections
© National Instruments Corporation 4-5 NI PCI-7390 User Manual
Figure 4-2. Power Supply Connections
Step and Direction Outputs
• Axis <1..4> Step (CW) ± and Dir (CCW) ± —These RS-422
differential signals are the stepper command outputs for each axis.
The PCI-7390 supports both major industry standards for stepper
command signals: step and direction, or independent clockwise (CW)
and counter-clockwise (CCW) pulse outputs.
The output configuration and signal polarity is software programmable
for compatibility with various third-party drives, as follows:
– When step and direction mode is configured, each commanded
step (or microstep) produces a pulse on the step output. The
direction output signal level indicates the command direction
of motion, either forward or reverse.
– CW and CCW mode produces pulses (steps) on the CW output for
forward-commanded motion and pulses on the CCW output for
reverse-commanded motion.
In either case, you can set the polarity of both outputs to active low or
active high. For example, with step and direction, you can make a logic
high correspond to either forward or reverse direction.
Optical
Isolation
Circuitry
DC/DC
Isolated Ground
User-Supplied
+24 V Supply
Is5 V OUT
PCI-7390
+24 V IN
Isolated Ground