II. Model Interpretation

PXI: PCI eXtensions for Instrumentation, compatible with standard PXI and PXIe mixed slots.

2529: NI 2500 series switch module, representing 128 cross points, dual-line matrix, electromechanical latch relay specifications.

Part number: 778739-01, etc.

Product status: In stock.

III. Technical Parameters

1. Channels and Topology

Total cross points: 128.

Configuration topology: 8×16 dual-line, 4×32 dual-line, dual 4×16 dual-line.

Relay type: Electromechanical latch relay (holds state during power loss).

Contact material: Silver-palladium alloy plated gold, low contact resistance, corrosion-resistant.

2. Electrical Characteristics

Maximum switching voltage: 150 VDC/150 VAC (CAT I), capable of withstanding 800V surge.

Maximum switching current: 1 A/channel; maximum carrying current: 2 A/channel.

Maximum switching power: 30 W (DC), 37.5 VA (AC).

On-state resistance: Initial < 1 Ω; life termination ≥ 2 Ω.

Thermal electromotive force: < 9 μV, suitable for low-voltage precision measurement.

Minimum switching current: 10 μA.

Relay life: Typical 10^7 times under resistive load.

3. Dynamic Performance

Scan rate: 120 cycles/second.

Switching time: < 5 ms (typical).

4. Physical and Environmental

Form: 3U PXI single slot (21.6 cm×2.0 cm×13.0 cm).

Weight: Approximately 210 g.

Operating temperature: 0–55 ℃; storage: -20–70 ℃.

Humidity: 10%–90% RH (no condensation).

Power consumption: 6 W at 5V supply; 2.5 W at 3.3V supply.

IV. Interface and Communication Configuration

Bus interface: Standard PXI mixed bus, supports hot plugging, plug-and-play, compatible with PXI/PXIe chassis.

Signal interface: Front panel 100-pin HDI high-density male connector, suitable for dual-line topology wiring.

Trigger and synchronization: PXI trigger line (0–7), supports hardware triggering, multi-module synchronous scanning.

Software driver: Companion NI-SWITCH driver, compatible with LabVIEW, TestStand, LabWindows/CVI, supports C/C++/Python API and IVI standard driver.

V. Core Functions

High-density matrix routing: 128 cross points, supports 8×16/4×32 / dual 4×16 three topologies, realizes flexible connection between any channels.

Low thermal electromotive force precision measurement: < 9 μV thermal electromotive force, suitable for thermocouples, sensors, etc. for high-precision acquisition of low-voltage weak signals.

Latch relay low power consumption: Holds channel state during power loss, no need for continuous power supply, reduces system energy consumption.

Built-in relay count: Built-in action count, supports predictive maintenance, early detection of aging relays.

High-speed synchronous scanning: 120 cycles/second scanning rate, hardware triggering synchronization, improves multi-channel testing efficiency.

VI. Application Scenarios

Precise signal testing system: Multi-channel acquisition and calibration of low-voltage signals such as thermocouples, strain gauges, sensors.

Automated ATE equipment: High-density functional testing and signal routing of consumer electronics, semiconductors, circuit boards.

Power and load testing: Voltage/current/resistance inspection and aging test of multiple power supplies, DC-DC modules.

Industrial control and monitoring: Multi-channel signal switching and status monitoring of control cabinets, transmitters, actuators. Aerospace and Defense: High-precision instruments, signal distribution and verification testing for avionics equipment.

VII. Operating and Maintenance Instructions

1. Installation and Wiring

The module must be unplugged and re-plugged while the power is off. After inserting into the PXI/PXIe slot, tighten the fixing screws.

Connect the 100-pin HDI interface cables according to the topological specification. Do not exceed 150V or 1A. Only CAT I measurement circuits are allowed.

The chassis and the tested equipment should be reliably grounded to reduce electromagnetic interference and electrostatic damage.

2. Software Configuration

Install the NI-SWITCH driver. Identify the module through NI-MAX and configure the matrix topology.

Implement functions such as channel switching, automatic scanning, and synchronous measurement through LabVIEW or text-based programming.

3. Daily Maintenance

After a regular power outage, clean the panel and interfaces with a dust-free soft cloth to prevent dust and liquids from entering the ports.

Maintain the working environment at 0–55 ℃ without condensation. Avoid areas with strong electromagnetic interference.

Avoid connecting inductive loads. If connecting inductive devices, a surge protection circuit must be added.

When plugging or unplugging the module or wiring, wear an anti-static wrist strap to prevent static discharge from damaging the internal circuits.