PXIe-2541 300 MHz 8×12 PXI Express RF Matrix Switch Module
The PXIe-2541 is a 300 MHz, 50 Ω PXI Express RF matrix switch module designed for flexible signal routing in automated test and measurement systems. Its 8×12 nonblocking matrix provides 96 crosspoints for connecting eight rows to twelve columns.
The module also provides Row In and Row Out connections for column expansion. Multiple PXIe-2541 modules can be cascaded to create larger matrices such as 8×24, 8×36, 8×48 and larger configurations.
Isolation relays disconnect unused portions of the switching matrix to help maintain RF performance and high open-channel isolation. The PXIe-2541 is suitable for routing signals among digitizers, function generators, RF sources, analyzers and devices under test.
Key Features of the PXIe-2541
- 8×12 nonblocking RF matrix topology
- 96 programmable crosspoints
- Expandable to 8×24, 8×36 and larger matrices
- Eight Row In and eight Row Out connections
- Twelve column connections
- DC to 300 MHz characterized bandwidth
- 50 Ω nominal characteristic impedance
- Twenty-eight front-panel MCX connectors
- 60 VDC or 42.4 Vpk maximum switching voltage
- 0.5 A maximum switching or carry current per channel
- 10 W maximum DC or RF power per channel
- Up to five maximum-power RF channels simultaneously
- Less than 3 dB Row In-to-column insertion loss
- Less than 1 dB Row In-to-Row Out insertion loss
- Greater than 75 dB typical open-channel isolation
- Less than -35 dB typical crosstalk
- 40-relay simultaneous-drive limit
- 0.25 ms maximum operate and release time
- 100 cycles/s scan rate
- Nonlatching reed relays
- PXI hardware trigger support
- NI-SWITCH and NI Switch Executive compatibility
PXIe-2541 Technical Specifications
| Product Model | PXIe-2541 |
|---|---|
| Part Number | 780587-41 |
| Product Type | Expandable PXI Express RF matrix switch module |
| Matrix Topology | 8×12 nonblocking matrix |
| Number of Rows | 8 |
| Number of Columns | 12 |
| Number of Crosspoints | 96 |
| Matrix Expansion | 8×24, 8×36, 8×48 and larger configurations |
| Switch Bandwidth | 300 MHz |
| Characteristic Impedance | 50 Ω nominal |
| Maximum Switching Voltage | 60 VDC or 42.4 Vpk |
| Maximum Switching or Carry Current | 0.5 A per channel |
| Maximum DC Switching or Carry Power | 10 W per channel |
| Maximum RF Power | 10 W per channel in a 50 Ω system |
| Simultaneous Maximum-Power RF Channels | 5 channels through 300 MHz |
| Initial DC Path Resistance | Less than 2.1 Ω, typical |
| End-of-Life Path Resistance | 3.1 Ω or greater, typical |
| Row In-to-Column Insertion Loss | Less than 3 dB; less than 2.1 dB typical through 300 MHz |
| Row In-to-Row Out Insertion Loss | Less than 1 dB; less than 0.5 dB typical through 300 MHz |
| Row In-to-Column VSWR | Less than 2.2; less than 1.6 typical through 300 MHz |
| Row In-to-Row Out VSWR | Less than 1.8; less than 1.5 typical through 300 MHz |
| Row In-to-Column Open Isolation | Greater than 75 dB, typical through 300 MHz |
| Row In-to-Row Out Open Isolation | Greater than 30 dB, typical through 300 MHz |
| Crosstalk | Less than -35 dB, typical through 300 MHz |
| Row In-to-Column Propagation Delay | Less than 6 ns, typical |
| Row In-to-Row Out Propagation Delay | Less than 1 ns, typical |
| Row In-to-Column Skew | Less than 2 ns, typical |
| Row In-to-Row Out Skew | Less than 0.1 ns, typical |
| Simultaneous Relay Drive Limit | 40 relays |
| Maximum Relay Operate Time | 0.25 ms |
| Maximum Relay Release Time | 0.25 ms |
| Scan Rate | 100 cycles/s |
| Mechanical Relay Life | 1 × 107 cycles, typical |
| Electrical Relay Life at 10 V, 100 mA | 1 × 107 cycles, typical |
| Electrical Relay Life at 20 V, 500 mA | 5 × 106 cycles, typical |
| Relay Type | Reed, nonlatching |
| Relay Contact Material | Rhodium |
| Input Trigger Sources | PXI trigger lines 0 through 7 |
| Minimum Input Trigger Pulse Width | 150 ns with digital filtering enabled |
| Output Trigger Destinations | PXI trigger lines 0 through 7 |
| Output Trigger Pulse Width | Programmable from 1 µs to 62 µs |
| Front-Panel Connectors | 28 MCX female connectors |
| Bus Interface | PXI Express |
| PXI Express Power Requirement | 10 W at 12 V and 2.5 W at 3.3 V |
| Module Format | 3U, one-slot PXI Express module |
| Dimensions | 21.6 cm × 2.0 cm × 13.0 cm |
| Weight | 410 g |
| Operating Temperature | 0°C to 55°C |
| Storage Temperature | -20°C to 70°C |
| Relative Humidity | 5% to 85%, noncondensing |
| Software Support | NI-SWITCH and NI Switch Executive |
PXIe-2541 Part Number and Accessories
| Item | Part Number | Description |
|---|---|---|
| PXIe-2541 | 780587-41 | 300 MHz, 8×12 expandable PXI Express RF matrix switch module |
| MCX-to-MCX Cable | 188374-0R15 | 0.15 m cable recommended for cascading matrix modules |
| MCX-to-MCX Cable | 188374-0R3 | 0.3 m MCX plug-to-MCX plug coaxial cable |
| MCX-to-MCX Cable | 188374-01 | 1 m MCX plug-to-MCX plug coaxial cable |
| MCX-to-BNC Cable | 188375-0R3 | 0.3 m MCX plug-to-BNC plug coaxial cable |
| MCX-to-BNC Cable | 188375-01 | 1 m MCX plug-to-BNC plug coaxial cable |
| MCX-to-SMB Cable | 188376-0R3 | 0.3 m MCX plug-to-SMB plug coaxial cable |
| MCX-to-SMB Cable | 188376-01 | 1 m MCX plug-to-SMB plug coaxial cable |
| MCX-to-SMA Cable | 188377-0R3 | 0.3 m MCX plug-to-SMA plug coaxial cable |
| MCX-to-SMA Cable | 188377-01 | 1 m MCX plug-to-SMA plug coaxial cable |
| 50 Ω MCX Terminator | 778831-01 | 50 Ω MCX termination rated for frequencies through 1 GHz |
The PXIe-2541 provides 28 MCX connectors: eight Row In connectors, eight Row Out connectors and twelve column connectors. The short 188374-0R15 MCX-to-MCX cable is recommended when cascading adjacent modules for matrix expansion.
8×12 RF Matrix Architecture
The PXIe-2541 contains eight rows and twelve columns. A programmable crosspoint is located at each row-and-column intersection, providing 96 possible matrix connections.
Software can connect any row to any column. Multiple crosspoints can operate simultaneously, allowing several instruments, sources and DUT connections to share the same switching system.
The 8×12 topology provides greater column density than the 8×9 configuration of the PXIe-2540.
96 Programmable Crosspoints
Each crosspoint represents a possible connection between one row and one column. NI-SWITCH controls these connections through channel and route names.
For example, R0 can be connected to C4 while R3 connects to C10. Additional routes can be created when they remain within the module’s relay-drive and electrical limits.
The large number of possible route combinations supports changing DUT types, test configurations and instrument assignments without rewiring the fixture.
Nonblocking Matrix Design
The nonblocking architecture allows any available row-to-column route to be established without matrix-topology restrictions caused by another independent connection.
Multiple instruments and DUT points can therefore operate through the matrix at the same time. The route configuration must still prevent incompatible sources from being connected together.
Column Expansion Architecture
The PXIe-2541 supports column expansion through its Row In and Row Out connections. Row Out connectors from one module are connected to the corresponding Row In connectors on the next module.
Cascading two modules creates an 8×24 matrix. Three modules create an 8×36 matrix, while four modules create an 8×48 configuration.
Additional modules can create 8×72, 8×96 and other larger matrices, subject to chassis space, relay-drive limits, insertion loss and software configuration.
Row In and Row Out Connections
Each of the eight matrix rows includes both a Row In and Row Out connector. Row In connects an external source or the output of a previous module to the matrix row.
Row Out passes that row to another module for column expansion. When expansion is not required, the Row Out connection can remain unused or be terminated according to the test-system design.
Matrix Expansion Cabling
NI specifies the 0.15 m MCX-to-MCX cable, part number 188374-0R15, for connecting Row Out ports to the corresponding Row In ports of an adjacent module.
Eight cables are required for every connection between two complete modules because each matrix has eight expandable rows.
Keep expansion cables short, equal in length and routed consistently to minimize additional insertion loss, skew and impedance variation.
Expansion Insertion Loss
Every additional cascaded module and cable increases insertion loss. A route in the first module passes through fewer expansion connections than a route in a later module.
The total loss depends on the selected column, number of cascaded modules, cable length and signal frequency. Apply path-specific correction when accurate amplitude measurements are required.
NI characterizes expansion performance for configurations through at least 8×96 using the recommended short MCX cables.
Isolation Relay Architecture
The PXIe-2541 contains isolation relays that disconnect unused columns and matrix sections from the active signal path.
This reduces unwanted parasitic loading and helps maintain RF bandwidth, insertion loss and open-channel isolation.
Isolation relays are managed as part of the module topology and switching routes through NI-SWITCH.
DC to 300 MHz Signal Routing
The PXIe-2541 is characterized for RF signal routing through 300 MHz. It can also route DC and lower-frequency analog signals within its voltage, current and power ratings.
This bandwidth supports digitizers, function generators, arbitrary waveform generators, oscilloscopes and other low-to-moderate-frequency RF instruments.
System bandwidth depends on the selected route, number of cascaded modules, cable length, impedance and fixture design.
50 Ω Characteristic Impedance
The module has a nominal characteristic impedance of 50 Ω. Connected sources, instruments, cables and fixtures should also use 50 Ω impedance.
Impedance mismatch increases reflected power and can degrade amplitude accuracy, VSWR and signal integrity.
Row In-to-Column Insertion Loss
Insertion loss from a Row In connector to a selected column is specified below 3 dB through 300 MHz, with a typical value below 2.1 dB.
The active route passes through matrix crosspoints and isolation relays. External cable and adapter losses must be added when calculating total system loss.
Row In-to-Row Out Insertion Loss
Insertion loss between Row In and Row Out is specified below 1 dB, with a typical value below 0.5 dB through 300 MHz.
This lower-loss expansion path allows the row signal to continue to subsequent PXIe-2541 modules. Total expansion loss increases with each module and cable stage.
VSWR Performance
Row In-to-column VSWR is specified below 2.2, with a typical value below 1.6 through 300 MHz.
Row In-to-Row Out VSWR is specified below 1.8, with a typical value below 1.5. NI indicates that expanded matrix configurations can maintain VSWR below 1.8 beyond 300 MHz when connected using the recommended expansion cables.
Open-Channel Isolation
Typical open-channel isolation from Row In to a column is greater than 75 dB through 300 MHz. This helps prevent signals from appearing on unselected column paths.
Typical Row In-to-Row Out open isolation is greater than 30 dB. External cable layout and fixture shielding also affect system-level isolation.
Matrix Crosstalk
Typical crosstalk is below -35 dB through 300 MHz. Crosstalk represents unwanted coupling between separate matrix routes.
High-amplitude signals should be separated from sensitive measurement paths when practical. Use shielded cables and careful fixture grounding to reduce external coupling.
Propagation Delay
Typical Row In-to-column propagation delay is less than 6 ns. Typical Row In-to-Row Out propagation delay is less than 1 ns.
An expanded route includes the delay of every Row In-to-Row Out stage, expansion cable and final row-to-column connection.
Channel-to-Channel Skew
Typical Row In-to-column skew is below 2 ns, while Row In-to-Row Out skew is below 0.1 ns.
External expansion and instrument cables can introduce additional skew. Use equal-length cables and characterize critical routes when timing alignment is important.
10 W RF Power Capability
The PXIe-2541 supports up to 10 W per RF channel in a 50 Ω system. Up to five channels can carry the maximum RF power simultaneously through 300 MHz.
Maximum permissible power decreases as frequency and the number of simultaneously loaded channels increase. Check the official PXIe power-derating curve for every high-power route configuration.
60 V and 0.5 A Electrical Ratings
The maximum switching voltage is 60 VDC or 42.4 Vpk. Maximum switching or carry current is 0.5 A per channel.
The maximum DC switching or carry power is 10 W per channel. Voltage, current and power limits apply simultaneously.
Switching Active RF Signals
NI recommends avoiding active RF switching whenever possible. A relay path can become momentarily unterminated while a route changes.
This temporary mismatch may reflect energy toward the RF source. Reduce or disable source output power before changing routes when required by the source documentation.
Fast Reed Relay Switching
The module uses nonlatching reed relays with maximum operate and release times of 0.25 ms.
Fast relay operation supports a scan rate of up to 100 cycles per second. Actual test throughput also depends on measurement aperture, source settling and DUT stabilization.
Nonlatching Relay Operation
The reed relays are nonlatching and return to their default state when module power is removed.
The application should still initialize all routes before applying signals because the required power-on configuration depends on the test system.
Relay Life
Typical mechanical relay life is approximately ten million cycles. At 10 V and 100 mA with a suitable resistive load, typical electrical life is also approximately ten million cycles.
At 20 V and 500 mA, typical electrical life is approximately five million cycles. Actual life depends on voltage, current, capacitance, inductance and switching frequency.
Capacitive and Inductive Load Protection
Reed relays can be damaged by capacitive inrush current and inductive flyback voltage.
Use current limiting, series resistance, flyback diodes, snubbers or other suitable protection according to the connected circuit.
Protection components should be selected carefully so they do not unacceptably reduce the required RF bandwidth.
PXI Hardware Triggering
The PXIe-2541 accepts input triggers from PXI trigger lines 0 through 7. The minimum pulse width is 150 ns with digital filtering enabled.
Output triggers can be routed to PXI trigger lines 0 through 7 with programmable pulse width from 1 µs to 62 µs.
Hardware triggering enables synchronization with digitizers, waveform generators and other PXI Express instruments.
Typical PXIe-2541 Applications
- Expandable automated RF switching systems
- High-channel-count signal routing
- Digitizer input selection
- Function-generator output routing
- Oscilloscope channel selection
- Multiple-instrument test systems
- Multiple-DUT production testing
- RF component characterization
- Semiconductor device testing
- Communications equipment validation
- Design verification testing
- Laboratory automation
High-Channel-Count Signal Routing
Multiple PXIe-2541 modules can create matrices with dozens of columns while maintaining eight common rows.
This allows a set of sources and instruments connected to the rows to access numerous DUT points connected to the expanded columns.
Digitizer and Oscilloscope Routing
Several DUT outputs can be connected to matrix columns, while digitizers and oscilloscope inputs are connected to rows.
Software selects the required crosspoints for each measurement. Path-specific loss and delay correction may be required for precision testing.
Function-Generator Routing
Function generators and arbitrary waveform generators can be connected to rows and routed to multiple DUT stimulus points connected to columns.
The nonblocking architecture allows several independent sources to operate simultaneously when the route configuration prevents electrical conflicts.
Multiple-DUT Production Testing
An expanded matrix can share a limited number of instruments among several DUT positions. Software changes routes according to the active fixture and test step.
This improves instrument utilization and reduces manual coaxial cable changes in production systems.
RF Component Characterization
The PXIe-2541 can route sources and measurement instruments to filters, amplifiers, attenuators and other RF components.
Calibration should include the selected matrix path, expansion cables and external fixture to remove switching-system loss from the measurement.
NI-SWITCH Software Support
The PXIe-2541 is controlled through the NI-SWITCH instrument driver. NI-SWITCH provides functions for initializing the module, connecting crosspoints, creating scan lists and configuring triggers.
The driver supports LabVIEW, LabWindows/CVI and compatible text-based programming environments. Multiple modules can be configured as an expanded matrix.
NI Switch Executive Integration
NI Switch Executive allows engineers to define logical route and route-group names instead of controlling individual crosspoints directly.
Named routes are especially useful for expanded systems containing hundreds of possible connections. Route validation can help prevent incompatible sources or unintended parallel paths.
PXI Express Chassis Integration
The PXIe-2541 occupies one slot in a compatible PXI Express chassis. Additional adjacent slots are required for every module added to an expanded matrix.
It can operate alongside digitizers, generators, oscilloscopes and other NI PXI and PXI Express modules.
Before installation, verify chassis slots, controller compatibility, cooling, MCX cable clearance and the installed NI-SWITCH version.
PXIe-2541 Troubleshooting
The PXIe-2541 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 restart NI Measurement & Automation Explorer.
A row does not connect to the selected column
Verify the row and column names used in the route command. Inspect the MCX cables, connectors and external fixture wiring.
An expanded matrix route does not work
Confirm that each Row Out connector is connected to the corresponding Row In connector on the next module. Check all eight expansion cables and verify the module order in software.
Insertion loss increases across later modules
This is expected because each additional module and expansion cable adds path loss. Apply route-specific correction and use the recommended 0.15 m expansion cables.
A route conflicts with another matrix connection
Review the complete route configuration for sources connected together through shared rows or columns. Use Switch Executive route validation to identify conflicts.
VSWR is too high
Verify that the complete system uses 50 Ω components. Check expansion cable length, MCX connector condition, load impedance and unused-port termination.
Isolation is lower than expected
Check whether unused matrix sections are properly disconnected. Improve external cable separation, shielding and fixture grounding.
The module cannot close every requested crosspoint
Count the simultaneously driven relays. The module has a 40-relay drive limit, so very large route groups may need to be divided or distributed differently.
A reed relay becomes unreliable
Check for capacitive inrush current or inductive flyback voltage. Inspect the connected circuit and add appropriate protection before replacing or servicing the module.
The scan rate is lower than expected
Review relay settling, measurement aperture, source stabilization, trigger configuration and software processing. The 100 cycles/s rating does not include every delay in the complete test system.
PXIe-2541 Comparison with Similar RF Matrix Modules
| Model | Primary Configuration | Best Suited For |
|---|---|---|
| PXI-2541 | 300 MHz, 8×12 expandable PXI matrix | Maintaining compatible legacy PXI matrix systems |
| PXIe-2540 | 350 MHz, 8×9 nonblocking matrix | Higher bandwidth without column expansion |
| PXIe-2541 | 300 MHz, 8×12 expandable matrix | High-column-count and scalable RF routing |
| PXI-2547 | 2.7 GHz, 8×1 RF multiplexer | Higher-frequency fixed multiplexer routing |
| PXIe-2543 | 6.6 GHz PXI Express RF multiplexer | Multi-gigahertz multiplexer applications |
PXIe-2541 vs PXIe-2540
The PXIe-2541 provides an expandable 8×12 matrix with 96 crosspoints and 300 MHz bandwidth. The PXIe-2540 provides an 8×9 matrix with 72 crosspoints and 350 MHz bandwidth.
Choose the PXIe-2541 when matrix expansion and additional columns are important. Choose the PXIe-2540 when nine columns are sufficient and the application benefits from its higher bandwidth.
PXIe-2541 vs PXI-2541
Both models provide the same fundamental 8×12 expandable matrix topology. The PXIe-2541 uses the PXI Express interface, while the PXI-2541 is intended for compatible legacy PXI systems.
Select the module according to chassis slot compatibility and the existing system architecture.
PXIe-2541 vs PXIe-2543
The PXIe-2541 provides a flexible 8×12 nonblocking matrix through 300 MHz. The PXIe-2543 supports much higher frequencies but uses a multiplexer-oriented topology.
Choose the PXIe-2541 for scalable many-to-many routing or the PXIe-2543 for multi-gigahertz signal selection.
Recommended Related Products
- PXI-2541 8×12 RF Matrix Switch Module
- PXIe-2540 350 MHz 8×9 RF Matrix Module
- PXI-2547 2.7 GHz 8×1 RF Multiplexer Module
- PXIe-2543 6.6 GHz RF Multiplexer Module
- View More NI PXI and PXI Express Modules
Selecting the Right PXI RF Matrix
Choose the PXIe-2541 when the application requires an expandable 8×12 matrix, 96 programmable crosspoints, 50 Ω impedance and signal routing through 300 MHz.
Choose the PXIe-2540 when expansion is unnecessary and slightly higher bandwidth is required. Select a high-frequency multiplexer when the signal exceeds the matrix module’s 300 MHz range.
Why Choose the PXIe-2541?
- Provides an 8×12 nonblocking RF matrix
- Offers 96 programmable crosspoints
- Expands to 8×24, 8×36, 8×48 and larger configurations
- Routes signals from DC through 300 MHz
- Maintains 50 Ω characteristic impedance
- Uses isolation relays to disconnect unused matrix sections
- Provides greater than 75 dB typical open-channel isolation
- Handles up to 10 W per RF channel
- Uses fast reed relays
- Provides Row In and Row Out expansion connectors
- Supports PXI hardware triggering
- Integrates with NI-SWITCH and NI Switch Executive
Frequently Asked Questions
What is the PXIe-2541?
The PXIe-2541 is a 300 MHz, 50 Ω PXI Express RF matrix switch module providing eight rows, twelve columns and 96 crosspoints.
What is the PXIe-2541 topology?
It uses an 8×12 nonblocking matrix topology.
How many crosspoints does the PXIe-2541 provide?
The module provides 96 programmable row-to-column crosspoints.
Can the PXIe-2541 matrix be expanded?
Yes. Multiple modules can be connected through their Row Out and Row In ports to create 8×24, 8×36, 8×48 and larger matrices.
How many cables are required between two modules?
Eight MCX-to-MCX expansion cables are required because every module has eight expandable rows.
What is the PXIe-2541 bandwidth?
The module is characterized for RF signal routing through 300 MHz.
What is the maximum switching voltage?
The maximum switching voltage is 60 VDC or 42.4 Vpk.
What is the maximum switching current?
The maximum switching or carry current is 0.5 A per channel.
What is the maximum RF power?
The maximum RF power is 10 W per channel, subject to frequency and simultaneous-channel derating.
What connectors does the PXIe-2541 use?
The module provides 28 MCX female connectors: eight Row In, eight Row Out and twelve column connections.
Does the PXIe-2541 use latching relays?
No. It uses nonlatching reed relays with rhodium contacts.
Which software controls the PXIe-2541?
The module is controlled through NI-SWITCH and can be configured with named routes using NI Switch Executive.
What is the PXIe-2541 part number?
The standard NI part number for the PXIe-2541 is 780587-41.
Request a Quote for the PXIe-2541
Contact us for current availability, lead time and project pricing for the PXIe-2541 300 MHz 8×12 PXI Express RF Matrix Switch Module. We can also help identify compatible MCX cables, terminators, PXI Express chassis and additional modules for building an expanded RF matrix.
