II. Model Interpretation

PXI: Standard 3U single slot, compatible with PXI/PXIe mixed slots, connects to the PXI trigger bus and the RTSI real-time synchronization bus.

7340: 73xx motion control series, 4 represents 4-axis independent control, 0 represents standard type (non-enhanced), different from 7344 (4-axis enhanced type), 7350 (8-axis).

Positioning: 4-axis high-performance servo/stepper motion control card, suitable for motion control scenarios with high precision, high dynamics, and multi-axis linkage.

III. Technical Parameters (25℃)

1. Motion Control Core

Control Axis Number: 4-axis independent/synchronous, compatible with servo or stepper motors.

Control Cycle: 62.5 μs per axis, total 4-axis cycle 250 μs.

Position Range: ±2³¹ counts (servo)/±2³¹ steps (stepper).

Speed: Servo 20 M counts/second; Stepper 4 M steps/second.

Acceleration: Servo 1244~512 M counts/second²; Stepper 2.44~512 M steps/second².

Control Mode: PID/PIVff/double loop control, with feedforward, S-curve smoothing, hardware breakpoints.

2. Analog I/O

Analog Output (AO): 4 channels ±10 V, 16 bits, servo command output.

Analog Input (AI): 8 channels ±10 V, 16 bits, sensor/feedback acquisition.

3. Encoder and Feedback

Encoder Interface: 4 channels A/B/Z phases, up to 4 MHz, supports incremental encoders.

Feedback Type: Encoder, analog quantity, pulse command, supports double-loop feedback.

4. Digital I/O

Channels: 32 TTL, bidirectional configurable, 16 input/16 output per channel.

Level: High ≥ 2.4 V, Low ≤ 0.4 V, maximum pull/hold current 8 mA.

5. Physical and Environment

Connector: 2×68-pin SCSI (motion I/O + digital I/O).

Power Supply: PXI backplane + 5 V/+3.3 V, no external power required.

Operating Temperature: 0 ℃ ~ 55 ℃.

Storage Temperature: -20 ℃ ~ 70 ℃.

Power Consumption: Approximately 15 W.

IV. Interface and Communication Configuration

1. Hardware Interface

Motion I/O (68-pin): 4 channels encoders, 4 channels AO, 8 channels AI, limit/origin, breakpoint input.

Digital I/O (68-pin): 32 TTL, used for triggering, interlock, status monitoring.

Backplane: PXI trigger bus (8 channels), RTSI bus, supports multi-module nanosecond-level synchronization (<100 ns).

2. Software and Drivers

Driver: NI-Motion, supports trajectory planning, closed-loop control, electronic gearing, fly saw.

Development Environment: LabVIEW, C/C++, Python, TestStand, supports real-time control.

Functions: On-board programming, hardware breakpoints (200 ns pulse), watchdog (63 ms), fault-safe shutdown.

V. Core Functions

4-axis high-speed closed-loop control, nanosecond-level synchronization

Each axis updates at 62.5 μs, supports servo/stepper mixed control; PXI/RTSI bus synchronization, multi-axis timing jitter <100 ns, meets precise linkage requirements.

On-board trajectory planning, independent real-time operation DSP + FPGA hardware implementation for linear / circular interpolation, electronic gearing, synchronous following, without occupying the host CPU, supporting offline execution of complex motion trajectories.

Rich I/O integration, integrated control

4 channels of 16-bit AO, 8 channels of 16-bit AI, 32 channels of TTL I/O, 4 channels of encoders, can be directly connected to motors, sensors, limit switches, simplifying the system architecture.

Advanced control algorithms and safety protection

PID + feedforward control, S curve acceleration and deceleration smoothing; hardware limit, software limit, watchdog, short circuit protection, automatic safe shutdown in case of faults.

Multi-module collaboration, system-level synchronization

Sharing clock and trigger with PXI data acquisition, vision, FPGA modules, building a unified time reference, suitable for complex automation system integration.

Six, applicable scenarios

Precision processing and manufacturing

PCB drilling, laser microprocessing, CNC precise positioning, semiconductor wafer handling, micron-level positioning accuracy.

Automation testing and verification

Multi-axis motion platform testing, sensor calibration, product lifespan testing, robot joint performance verification.

High-speed precise positioning system

Electronic manufacturing assembly machines, optical platforms, biological 3D printing, high-speed sorting machines, high dynamic response scenarios.

Servo / stepper motor control

Industrial robots, CNC machines, packaging machinery, textile equipment, multi-axis synchronous and联动 control.

Research and laboratory automation

Optical instruments， precision measurement equipment， automated experimental platforms， nanosecond-level synchronization and high-precision motion control.

Seven， usage and maintenance instructions

1. Installation and power-on

Disconnect power， insert into any slot of the PXI chassis， tighten screws and reliably ground； before powering on， check that the 68-pin cable has no short circuit / virtual connection to avoid damaging I/O channels. Keep the chassis ventilated during operation， environmental temperature ≤ 55℃， to avoid temperature accumulation affecting control accuracy.

2. Wiring and operation

Cables： Use shielded 68-pin SCSI cables， separate analog signals， encoder signals and digital signals for wiring to reduce crosstalk； encoder cable length ≤ 10 m to avoid signal attenuation.

Configuration： Set axis type (servo / stepper)， control mode， limit parameters， trajectory data in software； for the first run， perform no-load debugging first， confirm normal motion before connecting the load.

Synchronization： When synchronizing multiple cards， share PXI_TRIG or RTSI signals to ensure consistent timing； hardware breakpoints are used for precise triggering of external events.

3. Daily maintenance

Regularly clean 68-pin connectors， check the integrity of the cable shielding layer， add dust caps for long-term storage to prevent oxidation and dust from affecting contact reliability.

Calibration： Suggested once a year， use NI-Motion calibration tool， calibrate analog I/O accuracy， encoder zero point and limit trigger values.

Driver update： Regularly update NI-Motion driver and firmware to fix compatibility issues and optimize motion control stability.