Description

NI  PXI-7344  4-axis servo motion control module

Functional characteristics
Multi-axis programmable control: It can perform fully programmable motion control on up to four independent or coordinated axes, achieving various motion trajectory controls such as circular, linear, and point-to-point, and is suitable for a wide range of equipment including servo motors and servo hydraulic systems.
Multiple motion control modes: Supports various motion control modes such as position, speed and force control, which can meet the needs of different application scenarios.

High-speed and high-precision servo update: It features an enhanced PID/PIVff servo update function, with a speed of up to 62μs per axis. Position and speed feedback can be provided through orthogonal encoders or analog inputs, ensuring the stability and accuracy of the control system.
Rich I/O interfaces: Equipped with 32 digital I/O channels, dedicated motion I/O with limit and origin switches, as well as 8 multiplexed analog input channels (4 of which are user signals) and 4 analog output channels, it can be conveniently connected to external sensors, actuators and other devices.

High encoder feedback rate: Supports an encoder feedback rate up to 20MHz, enabling rapid acquisition of motor position and other information, further enhancing control accuracy.
Multi-program parallel operation: Up to 10 motion programs can be run simultaneously in a real-time, preemptive, and multi-tasking operating system environment, enhancing the flexibility and efficiency of motion control.

Support for RTSI bus: Supports NI’s proprietary Real-time System Integration (RTSI) bus, which can be synchronized with multiple IMAQ, DAQ or motion devices to a common timing or trigger event, facilitating the construction of complex automation systems.
Strong software support: It provides easy-to-use software tools and an additional motion VI library, which can be used with LabVIEW and also supports other application development software such as LabWindows/CVI, facilitating users’ programming and system configuration.
Compatibility with multiple buses: Suitable for PXI, PCI and 1394 bus computers, it can be flexibly integrated into different system architectures.

Technical parameters
Number of axes: 4 axes.
Digital I/O channels: 32.
Analog input resolution: 12 bits.
Analog input channels: 8 multiplexed analog input channels, among which 4 are user signals.
Analog output channels: 4.
PID update rate: The fastest is 62.5μs per axis, and the total for 4 axes is 250μs.
Trajectory update rate: The same as the PID update rate.
Position accuracy: The encoder feedback is ±1 orthogonal count, and the analog feedback is ±1 least significant bit (lsb).
Long-term speed accuracy: Based on the oscillator, ±100 ppm.
Speed range: 1 to ±20,000,000 counts per second.
Acceleration/deceleration range: 4,000 to 128,000,000 counts per second ².
The time range of the S-curve: 1 to 32,767 samples.
Gear ratio: ±32,767:1 to 1:32,767.
Encoder feedback rate: Up to 20MHz at most.
Operating temperature: 0 to 55°C.
Communication bus: Supports PXI, PCI and 1394 buses, and supports NI’s proprietary Real-time System Integration (RTSI) bus.
Connector: Provides a high-density 68-pin female VHDCI connector for motion I/O connections.

Application field
Wind tunnel measurement system In the wind tunnel measurement system used for functions such as aircraft configuration and component dynamic and static force measurement, the PXI-7344 motion controller board card can control the direction of the model and asymptotic encoder interface with the motion control board card, and send the direction information back to the system. Combined with other modules such as NI SCXI-1125, etc., it realizes the measurement of parameters such as pressure and force. High-speed port switching is achieved with the help of LabVIEW to shorten the operation cycle of the wind tunnel.

Mobile phone flip cover durability test system: The mobile phone flip cover durability test system based on virtual instrument technology is composed of PXI-8186 controller, PXI-7344, UMI-7764, servo unit and servo motor. The PXI-7344 sends out the motion control voltage signal, which is connected to the servo motor driver through UMI-7764 to control the servo motor to drive the paddles and levers to realize the opening and closing test of the mobile phone flip cover. It can test 4 mobile phones simultaneously, significantly improving the running speed. Moreover, the interface developed with LabVIEW is user-friendly. Repetitive operations can also be reduced through parameter configuration.

Inverted pendulum control system: Based on the PXI-1050 industrial control computer and PXI-7344 motion control card of NI Company, a simulation and real-time control experimental platform for the linear two-stage inverted pendulum LQR control system can be developed in the LabVIEW environment. This platform can provide design and simulation verification tools for LQR controllers, as well as a real-time monitoring environment. It can also utilize the 3D controls of LabVIEW to design a visual human-computer interaction interface, providing a good hardware-in-the-loop experimental environment for control theory research and teaching.

Full-size train traction test bench: In the full-size train traction test bench built based on LabVIEW and PXI modular instruments, various signals such as accelerometer signals can be collected through multiple NI DAQ devices on the PXI platform. Although the specific function of PXI-7344 is not explicitly mentioned in the text, in test scenarios similar to those involving motor control and multi-axis motion control, PXI-7344 can, with its multi-axis control capability and high-precision characteristics, be used to control the motor movement in the test bench and simulate the operating conditions of the train, etc.