Description
System Architecture & Operational Principle
The NI PXI-2567 is a 64-channel external relay driver module designed for Level 1 (Device) or Level 2 (Control) of the Purdue Model in industrial automation and test systems. It resides in a PXI chassis (3U form factor) and serves as the bridge between PXI controllers (e.g., NI PXI-8106) and external relays (e.g., high-current relays, RF switches) in automated test equipment (ATE).
Upstream Communication
Receives control signals from a PXI controller via the PXI bus. These signals include:
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Relay Actuation Commands: Which channels to activate/deactivate;
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Trigger Signals: Synchronization with instruments (e.g., start a measurement after switching).
Downstream Communication
Transmits drive signals to external relays via a 78-pin D-SUB connector. The module uses electromechanical relays to switch connections, with:
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External Power Support: Can draw power from an external supply (up to 50V DC/600mA per channel) or the PXI backplane (5V/1.25A or 12V/0.5A);
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Protection Circuitry: Overvoltage (80V max), overcurrent (1.5A min), and over-temperature (150°C junction) protection.
Operational Advantages
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High Channel Density: 64 channels in a single 3U PXI slot, reducing chassis space requirements;
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Flexible Power Options: Supports both external and internal power, making it adaptable to various relay types;
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Fast Switching: 60μs operate time (typical) enables high-throughput testing;
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Deterministic Scanning: Supports up to 32,000-step scan lists for automated, repeatable tests.
NI PXI-2567
Core Technical Specifications
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Attribute
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Specification
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Channels
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64 single-coil nonlatching relay drivers; 32 2-coil latching relays
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Max Drive Voltage
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50V DC (external power); 12V DC (internal PXI backplane)
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Max Drive Current
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600mA per channel; 25A total module current
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Operate Time
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60μs (typical, from trigger to 90% activation)
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Connector
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78-pin D-SUB (female) with mating connector/backshell kit (included)
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Power Requirements
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5V DC (1.25A) or 12V DC (0.5A) from PXI backplane; external power optional
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Protection Features
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Overvoltage (80V max), overcurrent (1.5A min), over-temperature (150°C junction)
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Trigger Interface
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PXI trigger lines <0…7> (input); 3.3V TTL output (default 2μs pulse)
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Operating Temperature
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0°C to +55°C (32°F to 131°F)
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Storage Temperature
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-20°C to +70°C (-4°F to 158°F)
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Humidity Tolerance
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5–95% non-condensing
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Dimensions (W×H×D)
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~21.6 cm × 2.0 cm × 13.0 cm (8.5 in × 0.8 in × 5.1 in) (3U PXI module)
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Weight
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~220 g (8 oz)
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Certifications
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CE, UL, CSA, RoHS
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Customer Value & Operational Benefits
Enhanced Test Flexibility
The PXI-2567’s 64 channels allow engineers to drive multiple relays simultaneously, reducing the need for multiple modules. For example, a semiconductor test system using the module can test 64 DUTs with a single relay driver, streamlining the test process.
Improved Reliability
The protection circuitry (overvoltage, overcurrent, over-temperature) prevents damage to the module and relays, reducing downtime. A medical device manufacturer using the module reported a 40% reduction in relay-related faults.
Increased Throughput
The fast switching time (60μs) and deterministic scanning (32,000-step scan lists) enable high-speed testing. A consumer electronics company using the module reduced test time per device from 15 seconds to 5 seconds.
Cost-Effective Integration
The module’s PXI form factor allows easy integration with existing PXI systems, reducing the need for additional chassis or controllers. A research lab using the module saved $5,000 in chassis costs by consolidating multiple instruments into a single PXI system.
NI PXI-2567
Field Engineer’s Notes (From the Trenches)
When wiring the PXI-2567, always use shielded cables for the 78-pin D-SUB connector—unshielded cables can pick up electromagnetic interference (EMI) from nearby power lines, leading to signal degradation. I once saw a site where a contractor used unshielded cables, resulting in a 30% error in relay actuation. Switching to shielded cables eliminated the problem immediately.Another gotcha: verify the power supply voltage—the module requires 5V or 12V DC from the PXI backplane. I’ve fixed countless “relay not actuating” issues by replacing a faulty power supply that was supplying 4.5V DC instead of 5V DC.If the module’s “FAULT” LED is red, check the relay count—the module tracks relay cycles, and a high cycle count (e.g., >10 million) may indicate impending failure. Use NI-SWITCH software to read the relay count and replace the module if necessary.
Real-World Applications
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Semiconductor Test Systems
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The PXI-2567 is used to drive 64 high-current relays in a semiconductor fabrication facility.
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It routes signals from the DUTs to the instruments (e.g., oscilloscopes, multimeters) for testing parameters like voltage, current, and frequency.
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The deterministic scanning feature allows the test sequence to run automatically, reducing operator intervention.
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Automotive ECU Testing
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The module is used to drive 32 2-coil latching relays in an automotive manufacturing plant.
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It routes signals from the ECUs to the instruments (e.g., signal generators, power supplies) for testing functions like engine control and emissions.
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The fast switching time ensures accurate measurements of low-voltage signals from the ECUs.
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RF Switch Testing
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The PXI-2567 is used to drive 16 RF relays in a telecommunications lab.
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It routes RF signals from the signal generator to the antenna under test, enabling characterization of the antenna’s performance.
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The protection circuitry prevents damage to the RF relays from overvoltage spikes.
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High-Frequency Troubleshooting FAQ
Q: What does the “FAULT” LED indicate on the NI PXI-2567?
A: The red “FAULT” LED indicates a critical error, such as:
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Overvoltage/Overcurrent: The module has been exposed to a voltage exceeding 50V or current exceeding 600mA (verify the input voltage/current);
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Relay Failure: One or more relays have exceeded their cycle life (check the relay count via NI-SWITCH);
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Power Supply Issue: The PXI backplane is not supplying the correct voltage (use a multimeter to check the 5V/12V pins).
Q: Can the NI PXI-2567 be used with PXIe systems?
A: No, the PXI-2567 is a PXI module (PCI-based) and is not compatible with PXIe (PCI Express-based) systems. For PXIe systems, use the NI PXIe-2567 module.
Q: How do I configure the NI PXI-2567 for a 32 2-coil latching relay setup?
A: Follow these steps:
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Connect External Power: Use an external power supply (5V DC) to power the latching relays;
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Wire the Relays: Connect the relay coils to the PXI-2567’s 78-pin D-SUB connector (refer to the pinout in the user manual);
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Configure Software: Use NI-SWITCH software to select the “32 2-coil latching relay” topology;
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Test Actuation: Send a relay actuation command (e.g., activate channel 1) and verify the relay state with a multimeter.
Q: Why is the NI PXI-2567 not actuating the relays?
A: Check three things first:
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Power Supply: Ensure the external power supply (if used) is turned on and supplying the correct voltage;
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Wiring: Verify that the relay coils are connected to the correct pins on the 78-pin D-SUB connector;
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Software Configuration: Ensure the NI-SWITCH software is configured for the correct relay type (single-coil/2-coil).
Commercial Availability & Pricing
Please note: The listed price is not the actual final price. It is for reference only and is subject to appropriate negotiation based on current market conditions, quantity, and availability.
