II. Model Interpretation

PXI: PCI eXtensions for Instrumentation, compatible with PXI/PXIe hybrid slots.

2522: 2500 series (general-purpose relay switch), 22 represents 53 channels, SPDT single-pole double-throw, 100V/2A specification.

Part Number: 778572-22.

Status: In stock (NI mainstream SPDT general-purpose switch module).

III. Technical Parameters

Channel Configuration

Relay Type: 53 independent SPDT (Form C, single-pole double-throw) non-retentive armature relay from NI.

Topology: 53 independent channels, each channel includes a common terminal (COM), normally open (NO), and normally closed (NC).

Electrical Characteristics

Maximum switching voltage: 100 VDC.

Maximum switching current: 2 A (per channel, switching / carrying).

On-state resistance: <0.5 Ω (typical).

Thermal offset: Low (suitable for precise measurement).

Relay lifespan: 10^7 times (resistive load, typical).

Contact material: Palladium-ruthenium alloy plated gold (low contact resistance, corrosion-resistant).

Dynamic Performance

Switching time: <5 ms (typical).

Scan rate: 145 cycles/second.

Physical and Environmental

Size: 3U PXI (21.6 cm × 2.0 cm × 13.0 cm).

Weight: 192 g.

Operating temperature: 0–55 °C; Storage: −20–70 °C.

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

Power consumption: 7 W (5 V), 2.5 W (3.3 V).

IV. Interface and Communication Configuration

Host Interface: PXI hybrid bus (compatible with PXIe/PXI), supports hot plugging and plug-and-play.

Signal Interface: 160-pin DIN 41612 female connector (front panel), each channel leads to COM/NO/NC, facilitating flexible wiring.

Trigger and Synchronization: PXI trigger line (0–7, minimum pulse width of 150 ns), supports multi-module synchronous scanning and timing control.

Driver Software: Compatible with NI-SWITCH, LabVIEW, TestStand, C/C++/Python API, supports IVI standard driver.

V. Core Functions

53 independent SPDT switching: Each channel can achieve dual selection of common terminal and NO/NC, suitable for signal switching, power on/off, load routing, without external relays.

Medium-power general switching: 100 V/2 A covering low-voltage power supply, sensors, actuators (heaters, fans, solenoid valves), balancing power and density.

Low-resistance low-noise precise switching: <0.5 Ω on-state resistance + low thermal offset, suitable for precise voltage/current signal routing and measurement.

Built-in relay count: Built-in action count, supports predictive maintenance, early replacement of aged relays.

Software programmable and scanning: Supports immediate control and list scanning, suitable for automated test sequences and real-time control.

VI. Application Scenarios

Automated Test (ATE): Signal selection, power switching, functional testing and aging testing for circuit boards, modules, and systems.

Signal routing and selection: Single-ended signal switching for sensors, instruments, communication equipment, enabling multi-signal shared measurement instruments.

Power and load control: Low-voltage power distribution, relay/contactor drive, heater/fan/电磁阀 control.

Industrial control and monitoring： Equipment status monitoring， alarm circuit control， small actuator drive.

Automotive electronic testing： Power/I/O interface testing for on-board ECU， sensors， actuators.

VII. Installation and Maintenance Instructions

Installation and Wiring

Module: Unplug and power off for insertion, insert into the PXI/PXIe hybrid slot, tighten the fixing screws of NI.

Wiring: Connect the 160-pin DIN interface according to the channel definition (COM/NO/NC), strictly avoid exceeding 100 V and 2 A.

Grounding: Connect the chassis to the system ground reliably to reduce electromagnetic interference.

Software Configuration

Install the NI-SWITCH driver, NI-MAX recognizes the module, configure the SPDT channel topology.

Programming: Call the switch VI in LabVIEW, or configure the test sequence in TestStand to achieve channel control and scanning.

Daily Maintenance

Cleaning: After power off, wipe the panel with a soft cloth to avoid liquid entering the DIN interface.

Environment: Working temperature 0–55 °C, avoid dust, moisture, and strong electromagnetic interference.

Protection Mechanism: Avoid overvoltage (>100 V), overcurrent (>2 A), inductive loads (without surge suppression), to extend the relay lifespan.

Static Protection: Wear an anti-static wristband when plugging and unplugging the module, ensure good grounding of the chassis.