National Instruments NI 9503 User manual

USER MANUAL AND SPECIFICATIONS
NI 9503
Stepper Drive
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2|ni.com |NI 9503 User Manual and Specifications
This document describes how to use the National Instruments 9503
module and includes specifications and pin assignments for the
NI 9503. Visit ni.com/info and enter rdsoftwareversion to
determine which software you need for the modules you are using.
For information about installing, configuring, and programming the
system, refer to the system documentation. Visit ni.com/info and
enter cseriesdoc for information about C Series documentation.
Note The safety guidelines and specifications in this
document are specific to the NI 9503. The other
components in the system may not meet the same safety
ratings and specifications. Refer to the documentation for
each component in the system to determine the safety
ratings and specifications for the entire system.
Safety Guidelines
Operate the NI 9503 only as described in these operating
instructions.
Hot Surface This icon denotes that the component may
be hot. Touching this component may result in bodily
injury.

NI 9503 User Manual and Specifications |© National Instruments |3
Caution Do not operate the NI 9503 in a manner not
specified in these operating instructions. Product misuse
can result in a hazard. You can compromise the safety
protection built into the product if the product is damaged
in any way. If the product is damaged, return it to
National Instruments for repair.
Safety Guidelines for Hazardous Locations
The NI 9503 is suitable for use in Class I, Division 2, Groups A, B,
C, D, T4 hazardous locations; Class I, Zone 2, AEx nA IIC T4, and
Ex nA IIC T4 hazardous locations; and nonhazardous locations
only. Follow these guidelines if you are installing the NI 9503 in a
potentially explosive environment. Not following these guidelines
may result in serious injury or death.
Caution Do not disconnect I/O-side wires or connectors
unless power has been switched off or the area is known
to be nonhazardous.
Caution Do not remove modules unless power has been
switched off or the area is known to be nonhazardous.

4|ni.com |NI 9503 User Manual and Specifications
Caution Substitution of components may impair
suitability for Class I, Division 2.
Caution For Division 2 and Zone 2 applications, install
the system in an enclosure rated to at least IP 54 as
defined by IEC 60529 and EN 60529.
Caution For Division 2 and Zone 2 applications, install
a protection device between the input signal and the Vsup
pin. The device must prevent the Vsup-to-channel voltage
from exceeding 42 V if there is a transient overvoltage
condition.
Caution For Zone 2 applications, connected signals
must be within the following limit:
Capacitance.......................... 0.2 μF max
Special Conditions for Hazardous Locations Use in
Europe
This equipment has been evaluated as Ex nA IIC T4 Gc equipment
under DEMKO Certificate No. 12 ATEX 1202658X. Each module
is marked II 3G and is suitable for use in Zone 2 hazardous
locations, in ambient temperatures of -40 °C ≤Ta ≤70 °C. If you are

NI 9503 User Manual and Specifications |© National Instruments |5
using the NI 9503 in Gas Group IIC hazardous locations, you
must use the device in an NI chassis that has been evaluated as
Ex nC IIC T4, EEx nC IIC T4, Ex nA IIC T4, or Ex nL IIC T4
equipment.
Caution You must make sure that transient disturbances
do not exceed 140% of the rated voltage.
Caution The system shall be mounted in an ATEX
certified enclosure with a minimum ingress protection
rating of at least IP54 as defined in IEC/EN 60529 and
used in an environment of not more than Pollution
Degree 2.
Caution The enclosure must have a door or cover
accessible only by the use of a tool.
Electromagnetic Compatibility Guidelines
This product was tested and complies with the regulatory
requirements and limits for electromagnetic compatibility (EMC)
as stated in the product specifications. These requirements and
limits are designed to provide reasonable protection against

6|ni.com |NI 9503 User Manual and Specifications
harmful interference when the product is operated in its intended
operational electromagnetic environment.
This product is intended for use in industrial locations. As such,
there is no guarantee that harmful interference will not occur in
a particular installation, when the product is connected to a test
object, or if the product is used in residential areas. To minimize
the potential for the product to cause interference to radio and
television reception or to experience unacceptable performance
degradation, install and use this product in strict accordance with
the instructions in the product documentation.
Furthermore, any changes or modifications to the product not
expressly approved by National Instruments could void your
authority to operate it under your local regulatory rules.
Caution To ensure compliance with the applicable
regulatory requirements, product installation requires
either special considerations or user-installed, add-on
devices. See the product installation instructions for
further information.

NI 9503 User Manual and Specifications |© National Instruments |7
Caution The inputs/outputs of this product can be
damaged if subjected to Electrostatic Discharge (ESD).
To prevent damage, industry-standard ESD prevention
measures must be employed during installation,
maintenance, and operation.
Special Guidelines for Marine Applications
Some products are Lloyd’s Register (LR) Type Approved for
marine (shipboard) applications. To verify Lloyd’s Register
certification for a product, visit ni.com/certification and
search for the LR certificate, or look for the Lloyd’s Register mark
on the product label.
Caution In order to meet the EMC requirements for
marine applications, install the product in a shielded
enclosure with shielded and/or filtered power and
input/output ports. In addition, take precautions when
designing, selecting, and installing measurement probes
and cables to ensure that the desired EMC performance is
attained.

8|ni.com |NI 9503 User Manual and Specifications
NI 9503 Hardware Overview
The NI 9503 is a stepper motor drive for use with 2-phase hybrid
stepper motors in either bipolar or unipolar winding configuration.
It uses software-programmable control algorithms that reduce
torque ripple, dampen high-speed resonance, and implements
smoother motion during microstepping.
The NI 9503 returns the motor current and bus voltage to the
LabVIEW FPGA module for use in a current PI loop and
antiresonance algorithms. NI 9503 status information such as drive
status and drive faults are also returned to the LabVIEW FPGA
module. Refer to the NI 9503 topic in the LabVIEW Help, available
by selecting Help»LabVIEW Help, for information about the
available status information.
Note National Instruments offers NEMA 8, NEMA 11,
NEMA 14, NEMA 17 and NEMA 23 stepper motors
compatible with the NI 9503. Go to ni.com/motion/
stepper for more information about NI stepper motors.
The NI 9503 reduces torque ripple at speeds near 1 RPS that are
caused by fourth harmonic disturbances. The torque ripple
smoothing algorithm is software programmable and can be tuned

NI 9503 User Manual and Specifications |© National Instruments |9
for any motor. Motors supported by National Instruments have
already been tuned for optimal torque smoothing.
The NI 9503 uses a software-programmable antiresonance
algorithm to reduce stepper motor resonance above 2 RPS. The
antiresonance algorithm allows a stepper motor to use more
available torque and run at higher speeds without stalling.
The NI 9503 supports software-programmable microstepping.
Microstepping divides full steps into smaller steps to create
smoother motion. The NI 9503 supports microstepping rates up to
256. When full-stepping, a resonance can occur, causing vibration
and reducing the motor torque. The NI 9503 offers the best
performance when combining microstepping with the torque
smoothing and antiresonance properties. Refer to the Step Resolver
topic in the LabVIEW Help, available by selecting Help»
LabVIEW Help, for information about microstepping options.
The NI 9503 allows for phase current reduction after the motor
stops moving. Unlike servo motors, stepper motor coils remain
fully energized when the motor is not moving. This allows for
strong holding torque, but generates substantial heat in the motor.
Many applications do not require maximum holding torque when
the motor is at rest, which means that the motor is wasting power.
The amount of current reduction and delay before current

10 |ni.com |NI 9503 User Manual and Specifications
reduction becomes active is software-programmable. Refer to the
Current Scheduler topic in the LabVIEW Help, available by
selecting Help»LabVIEW Help, for information about current
reduction.
Figure 1. NI 9503 Block Diagram
Current
Scheduler
Step
Resolver
Current
Loop
Fault
Monitor
Bridge
Controller
Fault
Detection
Current
Sense
Motor
Position
Setpoint
LabVIEW FPGA Module with SoftMotion NI 9503
Phase A & B
Current
PWM
Generator
Anti-
resonance
Bus
voltage
Power
Stage
Vsup
COM
+
–
Correction
Angle