PXIe-2575 196-Channel PXI Express Multiplexer Module
The PXIe-2575 is a high-density PXI Express multiplexer switch module designed for automated test equipment, production testing and multichannel signal routing. It can operate as a 196 × 1 one-wire multiplexer or as a 95 × 1 or 98 × 1 two-wire multiplexer.
The PXIe-2575 uses latching electromechanical relays and supports signals up to 100 V, current up to 1 A and switching power up to 60 W or 62.5 VA. Its high channel density allows one measurement instrument or source unit to connect to hundreds of test points from a single PXI Express slot.
Key Features of the PXIe-2575
- 196-channel high-density PXI Express multiplexer
- 196 × 1 one-wire topology
- 98 × 1 two-wire topology
- 95 × 1 two-wire topology
- 100 V maximum switching voltage
- 1 A maximum total switching or carry current
- 60 W or 62.5 VA maximum switching power per channel
- Greater than 20 MHz one-wire bandwidth
- Greater than 8 MHz two-wire bandwidth
- Less than 0.5 Ω initial DC path resistance
- 3 µV typical differential thermal EMF
- 140 cycles/s scan rate
- 1 ms typical relay operate time
- Latching electromechanical relays
- Field-replaceable relays
- 32,000-step scan-list capability
- Onboard relay-count tracking
- PXI hardware trigger support
- 200-position LFH Matrix 50 connector
- NI-SWITCH and NI Switch Executive support
PXIe-2575 Technical Specifications
| Product Model | PXIe-2575 |
|---|---|
| Part Number | 780587-75 |
| Product Type | High-density PXI Express multiplexer switch module |
| Number of Banks | 1 |
| One-Wire Topology | 196 × 1 multiplexer |
| Two-Wire Topologies | 95 × 1 or 98 × 1 multiplexer |
| Maximum Switching Voltage | 100 VDC or 100 VAC |
| Measurement Category | CAT I signal circuits |
| Maximum Total Current | 1 A switching or carry |
| Maximum Switching Power | 60 W or 62.5 VA per channel |
| Minimum Switch Load | 20 mV at 1 mA |
| Typical DC Isolation Resistance | Greater than 1 GΩ between channel and common terminals |
| Initial DC Path Resistance | Less than 0.5 Ω |
| End-of-Life Path Resistance | 1 Ω or greater |
| Typical Differential Thermal EMF | 3 µV |
| Maximum Differential Thermal EMF | Less than 12 µV |
| One-Wire Bandwidth | Greater than 20 MHz with 50 Ω termination |
| Two-Wire Bandwidth | Greater than 8 MHz with 50 Ω termination |
| Scan Rate | 140 cycles/s |
| Typical Relay Operate Time | 1 ms |
| Maximum Relay Operate Time | 3.4 ms |
| Mechanical Relay Life | 1 × 108 cycles |
| Relay Type | Electromechanical, latching |
| Relay Contact Material | Gold-covered palladium-ruthenium; some versions use gold-covered silver |
| Relay Serviceability | Field replaceable |
| Input Trigger Sources | PXI trigger lines 0 through 7 |
| Minimum Input Trigger Pulse Width | 150 ns |
| Output Trigger Destinations | PXI trigger lines 0 through 7 |
| Output Trigger Pulse Width | Software-selectable from 1 µs to 62 µs |
| I/O Connector | 200-position LFH Matrix 50 receptacle |
| Bus Interface | PXI Express |
| Power Requirement | 7.5 W at 12 V and 2.5 W at 3.3 V |
| Module Format | 3U, one-slot PXI Express module |
| Dimensions | 21.6 × 2.0 × 13.0 cm |
| Weight | 231 g |
| Maximum Altitude | 2,000 m at 25°C ambient temperature |
| Software Support | NI-SWITCH and NI Switch Executive |
PXIe-2575 Part Number and Accessories
| Item | Part Number | Description |
|---|---|---|
| PXIe-2575 | 780587-75 | 196-channel, 1- or 2-wire PXI Express multiplexer module |
| LFH200 to Bare-Wire Cable | 779038-01 | 200-pin LFH cable for connecting the module to a custom fixture |
| LFH200 to Four 50-Pin D-Sub Cable | 779038-02 | Breakout cable for connecting the module to four compatible 50-pin terminal blocks |
| TBX-50 Terminal Block | 779305-01 | 50-pin D-Sub screw-terminal block for external signal wiring |
| TBX-50B Terminal Block | 782866-01 | Updated 50-pin terminal block for field wiring and signal access |
The PXIe-2575 uses a 200-position LFH Matrix 50 connector. The 779038-02 breakout cable provides four 50-pin D-Sub connections, so as many as four TBX-50 or TBX-50B terminal blocks may be required for complete signal access.
High-Density Multiplexer Architecture
The PXIe-2575 routes one selected channel to a common terminal or common terminal pair. It allows a measurement instrument or signal source to access hundreds of test points without requiring a separate instrument for every channel.
The topology can be configured in software as a 196-channel one-wire multiplexer or as one of two available two-wire multiplexers. The selected topology determines how the physical connector pins are assigned.
196 × 1 One-Wire Topology
In the 196 × 1 configuration, one of 196 individual channels can be connected to the common terminal. This topology provides the highest available channel density.
One-wire operation is suitable for signals that share an external reference or return connection. It is commonly used for voltage monitoring, continuity testing and general-purpose signal selection.
98 × 1 Two-Wire Topology
The 98 × 1 configuration switches two conductors for each selected channel. One relay path connects the positive channel conductor to COM+, while the related path connects the negative conductor to COM−.
This topology is suitable for differential signals and circuits in which the measurement return must be switched along with the signal conductor.
95 × 1 Two-Wire Topology
The alternative 95 × 1 two-wire topology also switches paired positive and negative conductors. Its connector and common-terminal arrangement differs from the 98 × 1 configuration and is intended for applications requiring the corresponding signal assignment.
Before wiring the fixture, select the intended topology in NI-SWITCH and use its specific pinout. The same physical connector pins have different channel functions under different topologies.
One-Wire vs Two-Wire Operation
The one-wire topology provides 196 channels but switches only one conductor. The two-wire topologies switch both sides of a signal and provide either 95 or 98 measurement channels.
Choose one-wire operation when the signals have a suitable shared reference. Choose two-wire operation when the signal and return conductors must be isolated and switched together.
100 V Switching Capability
The PXIe-2575 can switch signals up to 100 V between channels or between a channel and ground. It is rated for Measurement Category I signal circuits.
The module must not be connected directly to building mains or Measurement Category II, III or IV circuits. When hazardous voltage is present on any terminal, safety-low-voltage signals must not be connected to other terminals on the module.
1 A Total Current Capability
The maximum total switching or carry current is 1 A. This limit applies to the module’s active signal path and must not be interpreted as 1 A available simultaneously through every channel.
The connected cable, terminal blocks, common terminals and custom fixture must also be rated for the expected current. Include transient and inrush conditions when evaluating the load.
60 W and 62.5 VA Switching Power
Maximum switching power is 60 W or 62.5 VA per channel. Voltage, current and switching-power limits must all be observed at the same time.
Inductive loads can produce voltage transients when opened. External suppression should be used when a motor, solenoid, relay coil or other inductive device could exceed the module’s voltage rating.
Low DC Path Resistance
Initial DC path resistance is specified at less than 0.5 Ω. Path resistance typically remains low through most of the relay’s useful life and then increases rapidly as the contact approaches end of life.
The complete signal path also includes cable, D-Sub terminal-block and fixture resistance. These additional components should be included when calculating voltage drop or measurement error.
Low Differential Thermal EMF
The PXIe-2575 provides 3 µV typical and less than 12 µV maximum differential thermal EMF. These characteristics help reduce errors when switching low-level DC signals.
For precision measurements, minimize temperature gradients across the module connector, cable, terminal block and test fixture. Allow suitable settling time after switching before acquiring the measurement.
20 MHz One-Wire Bandwidth
The one-wire topology provides greater than 20 MHz bandwidth with 50 Ω termination. This supports DC, low-frequency and moderate-frequency signals in automated test systems.
Actual system bandwidth depends on cable length, fixture construction, source and load impedance and the capacitance created by unused channels and relay paths.
8 MHz Two-Wire Bandwidth
The two-wire topologies provide greater than 8 MHz bandwidth with 50 Ω termination. Their bandwidth is lower than the one-wire configuration because each selected signal uses two switched conductors.
For high-frequency differential signals, keep cable and fixture paths short and verify performance using the complete signal-routing configuration.
140-Cycle-per-Second Scanning
The PXIe-2575 supports a scan rate of up to 140 cycles per second. A downloaded scan list can sequence through many channels without requiring the host processor to issue every individual relay command.
Overall measurement throughput also depends on relay settling time, instrument aperture, trigger configuration, software execution and device-under-test stabilization.
Latching Electromechanical Relays
The module uses latching electromechanical relays. A latching relay requires energy to change state but does not require continuous coil power to maintain the selected route.
Latching operation reduces steady-state power consumption and heat generation. The application should explicitly open or disconnect routes when a known safe state is required.
Relay Life and Replaceability
The expected mechanical relay life is 100 million cycles. Electrical life depends on the voltage, current, load type and switching frequency.
Representative electrical-life ratings include approximately 2.5 million cycles at 10 VDC and 100 mA resistive, one million cycles at 10 VDC and 1 A, 500,000 cycles at 30 VDC and 1 A and 100,000 cycles at 60 VDC and 1 A.
The relays are field replaceable when serviced according to the applicable NI procedure. Relay-count tracking can help identify heavily used channels before replacement is required.
Onboard Relay-Count Tracking
The PXIe-2575 records relay operations onboard the module. Test software can retrieve these counts to identify the most heavily used channels and plan preventive maintenance.
When possible, distributing frequently used measurements across several channels can balance relay usage and extend the service interval of the complete switch system.
Hardware Triggering
The module accepts input triggers from PXI trigger lines 0 through 7 with a minimum pulse width of 150 ns. Output triggers can be routed to the same trigger lines with a software-selectable pulse width from 1 µs to 62 µs.
Hardware triggering allows relay operations to be synchronized with digital multimeters, data acquisition modules, digitizers and other PXI Express instruments.
Typical PXIe-2575 Applications
- High-channel-count automated test equipment
- Digital multimeter channel expansion
- Production functional testing
- Printed circuit board testing
- Electronic device validation
- Multichannel voltage measurement
- Differential signal routing
- Sensor and transducer testing
- Component characterization
- Reliability and environmental testing
- Data acquisition channel expansion
- Laboratory automation
Digital Multimeter Channel Expansion
The PXIe-2575 can connect a digital multimeter to as many as 196 one-wire test points or up to 98 two-wire measurement points. Software selects the channel, allows the relay and signal to settle and then triggers the DMM.
This arrangement reduces instrument count while providing automated access to many device-under-test connections.
Production Test Systems
Production test equipment can use the PXIe-2575 to route measurement and stimulus signals to different fixture pins. High channel density reduces the number of switch modules and chassis slots required.
Hardware triggering and downloaded scan lists can coordinate switching with measurement operations, while relay-count tracking supports scheduled maintenance.
Sensor and Data Acquisition Systems
The module can route signals from many sensors or monitoring points to a shared measurement instrument. One-wire operation maximizes density, while two-wire operation provides switched signal and return paths.
Verify that sensor source impedance, common-mode voltage and grounding are compatible with the selected topology and measuring instrument.
NI-SWITCH Software Support
The PXIe-2575 is controlled through the NI-SWITCH instrument driver. NI-SWITCH provides functions for selecting the topology, connecting and disconnecting channels, creating scan lists, configuring triggers and reading relay counts.
The driver supports LabVIEW, LabWindows/CVI and compatible text-based programming environments. The topology should be selected before physical channel names are used in the test application.
NI Switch Executive Integration
NI Switch Executive allows engineers to replace physical channel names with descriptive signal aliases and named routes. This can simplify applications containing hundreds of switch connections.
Named routes also reduce the effort required when fixture wiring changes because the physical route definitions can be updated without rewriting the complete test sequence.
PXI Express Chassis Integration
The PXIe-2575 occupies one slot in a compatible 3U PXI Express chassis. It can operate alongside digital multimeters, data acquisition modules, digitizers, power supplies and other PXI Express instruments.
Before installation, verify chassis slot compatibility, cooling, controller support and the required NI-SWITCH version. Turn off chassis power before installing or removing the module.
PXIe-2575 Troubleshooting
The PXIe-2575 is not detected in NI MAX
Confirm that the module is fully installed in a compatible PXI Express slot. Check chassis power, controller communication and NI-SWITCH installation, then rescan the system in NI Measurement & Automation Explorer.
A requested channel does not connect
Verify that the selected topology matches the physical fixture wiring. Channel names and connector assignments differ between the 196 × 1, 98 × 1 and 95 × 1 topologies.
The two-wire measurement uses the wrong polarity
Check the CH+ and CH− pin assignments and the COM+ and COM− connections for the selected two-wire topology. Do not assume that one-wire channel numbering maps directly to two-wire channel names.
The signal path has excessive resistance
Inspect the LFH cable, D-Sub terminal blocks and fixture wiring. Compare the measured path resistance with the module’s initial specification and review relay-count data for the affected channel.
Measurements change after relay switching
Add sufficient settling time after connecting the channel. Check thermal gradients, cable capacitance, source impedance, grounding and the measurement instrument’s input configuration.
The scan rate is lower than expected
Review measurement aperture, settling delay, trigger timing and software processing. The 140-cycle-per-second specification does not include every delay required by the complete test.
A relay appears to be stuck
Use NI-SWITCH diagnostics and resistance measurements to check the route. Review the relay operation count and follow the applicable NI replacement procedure if the field-replaceable relay has failed.
Signals show unexpected crosstalk
Reduce cable length, improve shielding and separate high-level signals from sensitive low-level channels. Consider whether the affected one-wire channels share the same relay structure.
PXIe-2575 Comparison with Similar Multiplexer Modules
| Model | Primary Configuration | Best Suited For |
|---|---|---|
| PXIe-2575 | 196 one-wire or 95/98 two-wire channels, 100 V, 1 A | Maximum channel density with one- or two-wire routing |
| PXI-2575 | Similar 196/98/95-channel architecture with PXI hybrid interface | Maintaining existing conventional PXI systems |
| PXIe-2524 | 128 one-wire channels, multibank, 150 V, 2 A | Parallel one-wire routing using multiple banks |
| PXIe-2525 | 64 two-wire channels, multibank, 150 V, 2 A | Parallel differential and switched-return measurements |
| PXIe-2526 | 158 one-wire or 79 two-wire channels, 150 V, 2 A | Higher voltage and current with high single-bank density |
| PXIe-2527 | Up to 64 one-wire channels, 300 V, 2 A | Higher-voltage and multiwire measurements |
PXIe-2575 vs PXI-2575
The PXIe-2575 and PXI-2575 provide similar 196 × 1, 98 × 1 and 95 × 1 multiplexer topologies. Their primary difference is the chassis interface: the PXIe-2575 uses PXI Express, while the PXI-2575 uses a PXI hybrid interface.
Select the PXIe-2575 for PXI Express systems. Choose the PXI-2575 when maintaining a conventional PXI installation that requires the corresponding hybrid-bus version.
PXIe-2575 vs PXIe-2524
The PXIe-2575 provides more total channels and supports both one-wire and two-wire operation. The PXIe-2524 provides fewer channels but supports multiple independently controlled one-wire banks, 150 V operation and 2 A switching.
Choose the PXIe-2575 for maximum single-bank channel density. Choose the PXIe-2524 when parallel multibank routing or higher voltage and current ratings are more important.
PXIe-2575 vs PXIe-2526
The PXIe-2575 provides up to 196 one-wire channels or up to 98 two-wire channels at 100 V and 1 A. The PXIe-2526 provides 158 one-wire or 79 two-wire channels but supports up to 150 V and 2 A.
Select the PXIe-2575 when channel density is the main requirement. Select the PXIe-2526 when the application needs higher voltage or current capacity.
Recommended Related Products
- PXI-2575 High-Density Multiplexer Switch Module
- PXIe-2524 128-Channel Multibank Multiplexer
- PXIe-2525 64-Channel 2-Wire Multiplexer
- PXIe-2526 158-Channel Multiplexer Switch Module
- PXIe-2527 300 V Multiplexer Switch Module
- PXIe-4080 Digital Multimeter
- View More NI PXI and PXI Express Modules
Selecting the Right PXI Multiplexer
Choose the PXIe-2575 when the application requires the highest possible channel density, a single large multiplexer bank and a choice between one-wire and two-wire signal routing. It is particularly useful for expanding one measurement instrument across hundreds of test points.
Select the PXIe-2524 or PXIe-2525 when several independent banks must operate in parallel. Consider the PXIe-2526 when higher voltage and current are required or the PXIe-2527 when the application requires up to 300 V and multiwire measurement configurations.
Why Choose the PXIe-2575?
- Provides up to 196 one-wire channels
- Supports 95- and 98-channel two-wire topologies
- Routes signals up to 100 V and 1 A
- Offers greater than 20 MHz one-wire bandwidth
- Provides low path resistance and thermal EMF
- Uses latching electromechanical relays
- Includes field-replaceable relays
- Supports onboard relay-count tracking
- Provides deterministic PXI hardware triggering
- Integrates with NI-SWITCH and NI Switch Executive
Frequently Asked Questions
What is the PXIe-2575?
The PXIe-2575 is a high-density PXI Express multiplexer switch module that supports 196 one-wire channels or 95/98 two-wire channels.
Which topologies does the PXIe-2575 support?
It supports a 196 × 1 one-wire multiplexer, a 98 × 1 two-wire multiplexer and a 95 × 1 two-wire multiplexer.
What is the maximum switching voltage?
The maximum switching voltage is 100 V between channels or between a channel and ground for CAT I signal circuits.
What is the maximum switching current?
The maximum total switching or carry current is 1 A.
What is the maximum switching power?
The maximum switching power is 60 W or 62.5 VA per channel. Voltage, current and power limits must all be observed simultaneously.
What is the bandwidth of the PXIe-2575?
Bandwidth is greater than 20 MHz in the one-wire topology and greater than 8 MHz in the two-wire topologies.
What type of relays does the module use?
The PXIe-2575 uses latching electromechanical relays with gold-covered contact material.
Are the relays field replaceable?
Yes. Failed relays can be replaced by following the applicable NI service procedure.
Which cables are compatible with the PXIe-2575?
Compatible options include the 779038-01 LFH200-to-bare-wire cable and the 779038-02 LFH200-to-four-D-Sub breakout cable.
Which terminal blocks are compatible?
The 779038-02 breakout cable can connect the PXIe-2575 to TBX-50 or TBX-50B 50-pin terminal blocks.
Which software controls the PXIe-2575?
The module is controlled through NI-SWITCH and can be incorporated into named-route systems using NI Switch Executive.
What is the PXIe-2575 part number?
The standard NI part number is 780587-75.
Request a Quote for the PXIe-2575
Contact us for current availability, lead time and project pricing for the PXIe-2575 196-Channel PXI Express Multiplexer Switch Module. We can also help identify compatible LFH200 cables, TBX-50 terminal blocks, PXI Express chassis and related NI multiplexer modules for your automated test system.
