Chapter 3
Signal Connections
NI 951x User Manual
3-4
ni.com
Power Connections
The NI 951x drive interface modules require an external power supply. An
onboard regulator generates a +5 V output supply from the V
sup
input for
both internal and external usage. The positive terminal for the power supply
must be connected to V
sup
and the reference must be connected to COM.
Note
You can connect the external power supply to the V
sup
input provided on either
DSUB or MDR connectors. Do not connect more than one external power supplies to the
module.
Command Signals
The following signals control the stepper or servo drive.
Stepper Command Signals
Step (CW)± and Direction (CCW)±
These signals are the NI 9512 drive interface module stepper command
outputs.
The stepper output mode is software configurable for compatibility with
various third-party drives. The NI 9512 module supports both industry
standards for stepper command signals—step and direction, or
clockwise (CW) and counterclockwise (CCW) pulse outputs, as follows:
•
When step and direction mode is configured, each commanded step (or
microstep) produces a pulse on the step output. The direction output
indicates the commanded direction of motion, either forward or
reverse. Refer to Figure 3-1 for an illustration.
•
CW and CCW modes produce pulses on the CW output for
forward-commanded motion and pulses on the CCW output for
reverse-commanded motion. Refer to Figure 3-1 for an illustration.