PXI-2554 2.5 GHz 75 Ω 4×1 RF Multiplexer Switch
The PXI-2554 is a 2.5 GHz, 75 Ω, 4×1 PXI RF multiplexer switch module designed for routing video, broadcast and other high-frequency 75 Ω signals in automated test systems. It allows one common connection to select any one of four RF channels under software or hardware-triggered control.
With low insertion loss, controlled VSWR and high channel isolation, the PXI-2554 minimizes signal degradation when connecting video RF sources, analyzers, tuners, modulators and devices under test. Its 75 Ω impedance and mini-75 Ω SMB connectors make it particularly suitable for video and broadcast-oriented test platforms.
The module uses latching electromechanical relays and includes onboard relay-count tracking. This allows maintenance teams to monitor switching activity, estimate relay wear and reduce unexpected production-test downtime.
Key Features of the PXI-2554
- Single-bank 4×1 RF multiplexer topology
- DC to 2.5 GHz signal-routing capability
- 75 Ω nominal characteristic impedance
- 30 V maximum switching voltage
- 0.5 A maximum switching current per channel
- 0.5 A maximum carry current per channel
- 10 W maximum RF or switching power
- Less than 1.7 dB insertion loss through 2.5 GHz
- Less than 1.75 VSWR through 2.5 GHz
- Greater than 40 dB typical isolation through 2.5 GHz
- Less than 25 ps typical channel-to-channel skew
- 1 ns typical propagation delay
- Electromechanical latching relays
- Onboard relay-count tracking
- PXI hardware trigger support
- Five gold-plated mini-75 Ω SMB connectors
- NI-SWITCH and NI Switch Executive compatibility
PXI-2554 Technical Specifications
| Product Model | PXI-2554 |
|---|---|
| Part Number | 778572-54 |
| Product Type | PXI RF multiplexer switch module |
| Topology | Single 4×1 multiplexer, SP4T |
| Number of Banks | 1 |
| Number of Channels | 4 channels plus 1 common |
| Switch Bandwidth | 2.5 GHz |
| Characteristic Impedance | 75 Ω nominal |
| Internal Termination | No; unterminated 4×1 topology |
| Maximum Switching Voltage | 30 V |
| Maximum Switching Current | 0.5 A per channel |
| Maximum Carry Current | 0.5 A per channel |
| Maximum RF or Switching Power | 10 W channel-to-common |
| Initial DC Path Resistance | Less than 0.35 Ω typical |
| End-of-Life Path Resistance | 1.0 Ω or greater typical |
| Insertion Loss to 1 GHz | Less than 0.8 dB; less than 0.5 dB typical |
| Insertion Loss to 2 GHz | Less than 1.3 dB; less than 0.9 dB typical |
| Insertion Loss to 2.5 GHz | Less than 1.7 dB; less than 1.2 dB typical |
| VSWR to 1 GHz | Less than 1.25; less than 1.1 typical |
| VSWR to 2 GHz | Less than 1.5; less than 1.3 typical |
| VSWR to 2.5 GHz | Less than 1.75; less than 1.5 typical |
| Typical Isolation to 1 GHz | Greater than 47 dB |
| Typical Isolation to 2 GHz | Greater than 40 dB |
| Typical Isolation to 2.5 GHz | Greater than 40 dB |
| Channel-to-Channel Skew | Less than 25 ps typical |
| Propagation Delay | 1.0 ns typical |
| Rise Time | 75 ps typical, 10% to 90% |
| Relay Type | Electromechanical, latching |
| Maximum Relay Operate Time | 10.4 ms |
| Mechanical Relay Life | 1 × 106 cycles |
| Electrical Relay Life | 3 × 105 cycles at 30 V, 10 mA resistive |
| 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 | 5 gold-plated mini-75 Ω SMB jacks |
| Software Support | NI-SWITCH and NI Switch Executive |
| Bus Interface | PXI |
| Module Format | 3U, single-slot PXI/cPCI module |
| Dimensions | 21.6 × 2.0 × 13.0 cm |
| Weight | 204 g |
| Operating Temperature | 0°C to 55°C |
| Storage Temperature | -20°C to 70°C |
| Product Status | Discontinued by NI |
PXI-2554 Part Number and Accessories
| Item | Part Number | Description |
|---|---|---|
| PXI-2554 | 778572-54 | 2.5 GHz, 75 Ω, 4×1 PXI RF multiplexer switch module |
| Mini-75 Ω SMB Cable | 197211-0R3 | 0.3 m mini-75 Ω SMB plug-to-plug coaxial cable |
| Mini-75 Ω SMB Cable | 197211-01 | 1 m mini-75 Ω SMB plug-to-plug coaxial cable |
| Type F to Mini-75 Ω SMB Cable | 197210-0R3 | 0.3 m Type F female to mini-75 Ω SMB plug coaxial cable |
The PXI-2554 uses specialized mini-75 Ω SMB connectors rather than standard 50 Ω SMB or SMA connectors. Verify connector type, impedance, cable length and destination-interface compatibility before ordering replacement cables.
4×1 RF Multiplexer Architecture
The PXI-2554 contains four RF channels and one common connection. Software selects which channel connects to the common port, allowing one RF instrument to access four different signal paths.
The module can also be used in the reverse direction. One source connected to the common port can be routed to one of four devices, or four sources can be selected individually for connection to a common analyzer input.
Because the module is a multiplexer rather than a matrix, the channels are not intended to connect directly to one another. All selected signals route through the common port.
75 Ω Signal Routing
The PXI-2554 has a nominal 75 Ω characteristic impedance. This impedance is commonly used by video, broadcast, cable television and other coaxial signal systems.
Using 50 Ω cables or instruments in a 75 Ω path creates an impedance mismatch that can cause reflections and amplitude errors. Use compatible 75 Ω cables, adapters, sources and loads whenever the specified RF performance is required.
DC to 2.5 GHz Bandwidth
The PXI-2554 routes signals from DC through 2.5 GHz. This broad operating range supports baseband video, high-frequency video, broadcast RF, cable-device testing and general-purpose 75 Ω signal routing.
System bandwidth depends on the complete path. Cables, adapters, fixtures and connected instruments can reduce bandwidth or increase insertion loss beyond the switch module’s specifications.
Unterminated Multiplexer Design
The PXI-2554 is an unterminated 4×1 multiplexer. Unselected channels are not internally connected to 75 Ω terminations.
This design avoids the additional loading and power dissipation associated with internal termination. However, unused ports may require external termination when reflections could affect a source or measurement.
Choose the related PXI-2555 when internal termination of the disconnected paths is required by the application.
Low Insertion Loss
The specified insertion loss is less than 0.8 dB through 1 GHz, less than 1.3 dB through 2 GHz and less than 1.7 dB through 2.5 GHz.
Typical insertion loss is below 0.5 dB at 1 GHz, below 0.9 dB at 2 GHz and below 1.2 dB at 2.5 GHz. This helps preserve signal amplitude in video and RF measurements.
For precision amplitude measurements, characterize the switch, cable and fixture as one complete signal path and apply frequency-dependent correction.
VSWR Performance
The PXI-2554 provides a specified VSWR below 1.25 through 1 GHz, below 1.5 through 2 GHz and below 1.75 through 2.5 GHz.
Good VSWR performance helps reduce reflected power and amplitude ripple. Connector condition, cable quality and the impedance of external instruments remain important parts of total system performance.
Channel Isolation
Typical isolation is greater than 47 dB through 1 GHz and greater than 40 dB through 2.5 GHz. Isolation reduces leakage from inactive RF channels into the selected path.
High-level signals can still couple through external cables, adapters or fixtures. Keep strong and sensitive signal cables separated, use shielded accessories and terminate unused external paths where appropriate.
Propagation Delay and Channel Skew
Typical propagation delay through the selected signal path is approximately 1 ns. Typical channel-to-channel skew is less than 25 ps, and typical 10% to 90% rise time is approximately 75 ps.
These characteristics make the module suitable for fast video and pulse signals. External cable lengths should be matched when timing alignment between routes is important.
30 V, 0.5 A and 10 W Ratings
The PXI-2554 supports switching voltages up to 30 V and switching or carry current up to 0.5 A per channel. Maximum channel-to-common switching or RF power is 10 W.
Voltage, current and power limits apply simultaneously. A signal below 30 V can still exceed the module rating if its current or total power is too high.
Avoid Switching Active RF Signals
NI recommends against switching active RF signals whenever possible. During relay movement, the selected path becomes momentarily unterminated, which can reflect RF energy toward the signal source.
Some generators and amplifiers can be damaged by reflected power. Reduce or disable the source before changing channels, then restore the output after the relay has settled.
Switching active RF signals below 0 dBm may also degrade signal integrity and reduce relay life. Cold switching is recommended for maximum relay longevity.
Latching Electromechanical Relays
The PXI-2554 uses latching electromechanical relays. A latching relay maintains its selected state without continuously applying coil power, helping reduce module power consumption and heat.
Electromechanical contacts offer low path resistance and low insertion loss. Unlike solid-state switches, however, mechanical relays have a finite service life that depends on switching activity and electrical load.
Relay Life and Monitoring
Expected mechanical relay life is approximately 1 × 106 cycles. Expected electrical life is approximately 3 × 105 cycles when switching a 30 V, 10 mA resistive load under the documented conditions.
Onboard relay-count tracking records channel operations. Maintenance teams can use this information to identify heavily used paths and replace or rotate switching resources before a relay failure interrupts production.
Hardware-Triggered Switching
The PXI-2554 accepts input triggers and exports output triggers through PXI trigger lines 0 through 7. The minimum input pulse width is 150 ns when digital filtering is enabled.
Output trigger pulse width is programmable from 1 µs to 62 µs. Hardware triggering allows channel changes to be synchronized with digitizers, generators and other PXI instruments.
NI-SWITCH Software Support
The PXI-2554 is controlled using the NI-SWITCH instrument driver. NI-SWITCH provides functions for module initialization, channel connection, disconnection, scanning, triggering and relay-count monitoring.
The driver supports LabVIEW, LabWindows/CVI and compatible text-based programming environments. Check operating-system and driver compatibility when installing the discontinued module in an older PXI controller.
NI Switch Executive Integration
NI Switch Executive allows engineers to assign meaningful names to RF sources, analyzers, DUT connections and switch routes. Named routes are easier to understand than physical channel identifiers embedded throughout the test code.
The software can also coordinate the PXI-2554 with other PXI RF switches when a test system requires additional channels or more complex routing.
Typical PXI-2554 Applications
- High-frequency video signal routing
- Broadcast equipment testing
- Cable television device validation
- Video tuner stimulus and response testing
- RF analyzer input selection
- Signal generator output distribution
- Set-top box functional testing
- Video modulator testing
- Automated production test equipment
- 75 Ω RF component characterization
- Laboratory video test automation
- Device-under-test channel selection
- Coaxial cable and connector testing
- Electronic assembly validation
Video RF Testing
The 75 Ω impedance makes the PXI-2554 well suited to video and broadcast-oriented RF systems. It can select different tuners, modulators, receivers or signal paths for connection to one analyzer.
Low insertion loss and controlled VSWR help maintain video RF signal quality. External termination should be considered because the PXI-2554 does not terminate inactive channels internally.
Tuner and Receiver Testing
A common RF source can be routed to four tuner or receiver inputs, or four device outputs can be selected for measurement by one analyzer.
For parallel stimulus-and-response testing, consider the dual-bank PXI-2556, which provides two independent 4×1 multiplexers in one module.
Automated Production Testing
In production systems, the PXI-2554 can replace manual coaxial patching and allow test software to select each product or fixture connection automatically.
Relay-count tracking helps production engineers monitor switching activity and schedule maintenance before relay wear causes intermittent failures or increased insertion loss.
PXI-2554 Troubleshooting
The PXI-2554 Is Not Detected in NI MAX
Confirm that the module is fully installed in a compatible PXI or hybrid slot. Check chassis power, controller communication and NI-SWITCH installation, then restart the system and rescan for hardware.
No Signal Appears at the Common Port
Verify that the correct channel is connected to COM. Check the signal source, mini-75 Ω SMB cable and destination instrument, then confirm the NI-SWITCH route name.
The Signal Level Is Lower Than Expected
Account for module insertion loss, cable attenuation and fixture loss. Inspect the connectors and characterize the complete signal path when accurate amplitude correction is required.
The Signal Has Excessive Reflections
Confirm that the source, switch cables and load all use 75 Ω impedance. Add appropriate external terminations to unused channels and replace damaged or incorrectly rated cables.
An Unselected Signal Leaks into the Output
Review the physical cable arrangement and external fixture. Strong signals can couple through external components even when the module meets its isolation specification.
The RF Source Shuts Down During Switching
The source may be detecting reflected power while the relay is moving and the signal path is temporarily unterminated. Disable or reduce the RF output before changing routes.
A Channel Has Excessive Resistance
Inspect the cable and connector before evaluating the relay. Compare the affected route with other channels and check its relay count. End-of-life contacts may show rapidly increasing resistance.
The Hardware Trigger Does Not Advance the Route
Verify the selected PXI trigger line, trigger direction, pulse width and scan configuration. Start the scan list before the first trigger is generated.
Relay Life Is Shorter Than Expected
Check for active-signal switching, excessive current, capacitive inrush or inductive transients. Use cold switching and external protection whenever the application permits.
PXI-2554 Comparison with Similar 75 Ω RF Switches
| Model | Primary Configuration | Best Suited For |
|---|---|---|
| PXI-2554 | 2.5 GHz, 75 Ω, unterminated 4×1 multiplexer | Single-bank video RF routing with external termination |
| PXI-2555 | 2.5 GHz, 75 Ω, terminated 4×1 multiplexer | Applications requiring internal termination on inactive paths |
| PXI-2556 | 2.5 GHz, 75 Ω, dual 4×1 multiplexer | Parallel stimulus-and-response video RF testing |
| PXI-2557 | 2.5 GHz, 75 Ω, 8×1 multiplexer | Routing a larger number of video RF channels to one instrument |
| PXI-2558 | 2.5 GHz, 75 Ω, four independent SPDT relays | Building custom RF networks and changeover routes |
| PXI-2559 | 75 Ω RF relay architecture | Independent general-purpose video RF switching |
PXI-2554 vs PXI-2555
The PXI-2554 is an unterminated 4×1 multiplexer, while the PXI-2555 provides internal termination for disconnected signal paths. Both are designed for 75 Ω signals through 2.5 GHz.
Choose the PXI-2554 when the external system supplies its own termination or when unused channels should remain unterminated. Choose the PXI-2555 when internal termination is needed to reduce high-power reflections from open channels.
PXI-2554 vs PXI-2556
The PXI-2554 contains one 4×1 multiplexer bank. The PXI-2556 contains two independent 4×1 multiplexer banks.
Select the PXI-2554 for one source-selection or instrument-selection path. Select the PXI-2556 when two RF paths must operate independently, such as simultaneous stimulus and response routing.
PXI-2554 vs PXI-2557
The PXI-2554 provides four selectable channels, while the PXI-2557 provides an 8×1 configuration for higher channel count.
Choose the PXI-2554 for compact four-channel switching. Select the PXI-2557 when as many as eight video RF signals must share one source or analyzer.
Recommended Related Products
- PXI-2555 Terminated 4×1 RF Multiplexer
- PXI-2556 Dual 4×1 RF Multiplexer
- PXI-2557 8×1 RF Multiplexer
- PXI-2558 Quad SPDT RF Relay Module
- PXI-2559 75 Ω RF Relay Module
- View More NI PXI and PXI Express Modules
Selecting the Right 75 Ω RF Switch
Choose the PXI-2554 when the application requires one 4×1 multiplexer, 75 Ω impedance, operation through 2.5 GHz and external control of unused-port termination.
Choose the PXI-2555 for internally terminated operation, the PXI-2556 for two independent 4×1 banks or the PXI-2557 when a higher 8×1 channel count is required.
Why Choose the PXI-2554?
- Routes four 75 Ω RF channels to one common port
- Supports signals from DC through 2.5 GHz
- Provides low frequency-dependent insertion loss
- Maintains controlled VSWR and channel isolation
- Handles up to 30 V and 0.5 A
- Supports as much as 10 W RF power
- Uses latching electromechanical relays
- Provides onboard relay-count tracking
- Supports deterministic PXI hardware triggering
- Integrates with NI-SWITCH and NI Switch Executive
Frequently Asked Questions
What is the PXI-2554?
The PXI-2554 is a 2.5 GHz, 75 Ω, 4×1 PXI RF multiplexer used for automated video, broadcast and high-frequency signal routing.
What is the PXI-2554 part number?
The standard NI part number for the PXI-2554 is 778572-54.
What is the PXI-2554 topology?
It provides a single 4×1 multiplexer, with four selectable channels and one common connection.
What is the switch bandwidth?
The module routes signals from DC through 2.5 GHz.
Is the PXI-2554 a 50 Ω or 75 Ω switch?
It is a 75 Ω RF switch intended primarily for video and broadcast-related applications.
Are the unused channels internally terminated?
No. The PXI-2554 is unterminated. Select the PXI-2555 when internal termination is required.
What is the maximum RF power?
The maximum channel-to-common RF or switching power is 10 W, subject to the 30 V and 0.5 A limits.
What type of connectors does it use?
The front panel provides five gold-plated mini-75 Ω SMB jacks.
What is the maximum insertion loss?
Insertion loss is less than 0.8 dB through 1 GHz, less than 1.3 dB through 2 GHz and less than 1.7 dB through 2.5 GHz.
Does the PXI-2554 support relay-count tracking?
Yes. Onboard relay-count tracking helps monitor switching usage and plan preventive maintenance.
Which software controls the PXI-2554?
The module is controlled using NI-SWITCH and can be integrated into named-route applications with NI Switch Executive.
Is the PXI-2554 still available from NI?
No. NI identifies the PXI-2554 as no longer available. Used, refurbished and new-surplus modules may remain available through specialized test-equipment suppliers.
Request a Quote for the PXI-2554
Contact us for current availability, condition, testing options and project pricing for the PXI-2554 2.5 GHz 75 Ω 4×1 RF Multiplexer. We can also help identify compatible mini-75 Ω SMB cables, PXI chassis and related PXI-2555, PXI-2556 or PXI-2557 switch modules.
