Model Explanation

PXI: PXI bus standard (PCI eXtensions for Instrumentation)

2556: Product serial number, specifically referring to the dual 4×1 75Ω RF multiplexer

Full name: PXI-2556 / 778572-56 → 2.5 GHz 75Ω Dual 4×1 Multiplexers (Dual SP4T)

Topological alias: NISWITCH_TOPOLOGY_2556_DUAL_4X1_MUXNI Technical Specifications

RF Performance

Bandwidth: DC～2.5 GHz

Characteristic Impedance: 75 Ω (suitable for video / CATV) NI

Terminal Matching: No built-in terminal (external matching)

Insertion Loss: ≤ 0.7 dB @ 2.5 GHz

VSWR: ≤ 1.4:1 @ 2.5 GHz

Channel Isolation: ≥ 55 dB @ 2.5 GHz

Switching and Electrical

Topology: Dual 4×1 (Dual SP4T), two independent groups A/B, each group 4 inputs 1 output NI

Relay Type: RF Pneumatic Relay (latching)

Maximum Switching Voltage: 30 V NI

Maximum Channel Current: 0.5 A (per channel) NI

Maximum RF Power: 10 W (25°C) NI

Relay Lifespan: ≥ 10⁶ times (typical value)

Control Interface: PXI Bus (NI-SWITCH Driver)

Physical and Environmental

Size: Standard PXI 3U Single Slot

Weight: Approximately 0.45 kg (8.0 oz)

Connectors: Front panel 8×BNC inputs (A1-A4, B1-B4) + 2×BNC outputs (COMA, COMB) NI

Operating Temperature: 0～55°C

Storage Temperature: -40～70°C

Interface and Communication Configuration

Front Panel Interface

Bank A: CH1A～CH4A (4×BNC inputs), COMA (1×BNC output) NI

Bank B: CH1B～CH4B (4×BNC inputs), COMB (1×BNC output) NI

Impedance: All 75Ω, no built-in terminal

Backplane and Control

PXI Backplane: 3U Single Slot, compatible with PXI-1/PXIe mixed slots

Power Supply: PXI Backplane ±15 V, 5 V power supply

Trigger: Supports PXI TTL0～TTL4 hardware trigger, software immediate trigger

Driver: NI-SWITCH, supports LabVIEW, TestStand, CVI

Core Function

Dual Independent RF Routing: Two groups A/B, 4-way 1-way parallel switching, improving test efficiency

75Ω Broadband Signal Transmission: DC～2.5 GHz, suitable for video / CATV / RF component testing NI

Low Loss High Isolation: Low insertion loss, low VSWR, high isolation, ensuring signal integrity

Relay Lifespan Tracking: Built-in counter, predictive maintenance, reducing downtime

PXI Plug-and-Play: Standard driver, quick integration into automated test system

Application Scenarios

Parallel Testing of Video / Cable Television (CATV): Dual-channel signal routing, improving test throughput

Batch Testing of RF Components: Dual 4×1 architecture, parallel testing of filters, amplifiers, attenuators

Aerospace / Defense: Multi-channel RF signal switching, satellite communication equipment testing

Semiconductor Testing: Parallel verification of RF chips, transceivers

Industrial ATE: Parallel testing of RF / Video functions for mass-produced electronic products

User and Maintenance Instructions

Installation and Configuration

Insert into the 3U single slot of PXI, fix the panel

Install NI-SWITCH driver, identify the hardware

Configure the topology as Dual 4×1 Mux NI

Connect BNC cables, avoid excessive force bending; externally, connect a 75Ω terminal to prevent reflection

Operation Points

RF Power Limitation: Single-channel RF power ≤ 10 W at 25°C, temperature reduction for over-temperature conditions NI

Avoid Static Electricity: Ground before operation to prevent RF relays from being damaged by static electricity

Trigger Method: Software immediate trigger or PXI TTL hardware trigger, synchronize test process Parallel control: Two independent groups A/B for control, capable of switching to different channels simultaneously

Maintenance and calibration

Life monitoring: Read the number of times the relay is closed through NI-SWITCH, with an alert at 10⁶ times

Regular calibration: Calibrate insertion loss, VSWR, and isolation every year to ensure test accuracy

Environmental requirements: Working temperature 0-55°C, humidity 10%-90% (no condensation)

Storage: -40-70°C, dry and dust-proof, clean connectors before long-term storage