Description
NI SCXI-1193 | 500 MHz RF Multiplexer Switch | 32-Channel SCXI Switching
Key Technical Specifications
| Parameter | Specification |
|---|---|
| Model | SCXI-1193 |
| NI part number | 776572-93 |
| Module type | RF relay multiplexer/switch |
| Platform | NI SCXI |
| RF bandwidth | DC to 500 MHz |
| Channel count | 32 |
| Characteristic impedance | 50 Ω nominal |
| Relay type | Electromechanical, latching |
| Standard topology | 8×1 multiplexer |
| Other topology | 16×1 and 32×1 configurations |
| Custom topology | Flexible sparse matrix |
| Maximum scan rate | 100 operations/s |
| Mechanical relay life | Approximately 5 × 10⁷ operations |
| Electrical relay life | Approximately 3 × 10⁵ operations |
| Contact material | Silver-palladium and gold |
| RF insertion loss | <0.9 dB, DC–200 MHz in 8×1 configuration; <1.6 dB, 200–500 MHz |
| Impedance | 50 Ω nominal |
| Configuration | NI-SWITCH / Measurement & Automation Explorer |
| Status | Discontinued |
The RF specifications above are consistent with NI’s archived technical material. The SCXI-1193 uses latching electromechanical relays and is designed around 50 Ω RF signal paths.
Product Introduction
The NI SCXI-1193 provides programmable RF signal routing inside an SCXI test and measurement system. Its 32 channels can be arranged into standard multiplexer configurations or custom switching structures, allowing one instrument channel to be connected selectively to multiple RF sources or measurement points. NI specifies operation through 500 MHz.
The important engineering characteristic is its 50 Ω RF architecture. The module is intended for high-frequency instrumentation, including integration with PXI waveform generators and oscilloscopes, rather than low-frequency industrial analog acquisition.
SCXI-1193
Application Scenarios & Field Pitfalls — Engineer’s Perspective
Engineering Pain Point
The SCXI-1193 is frequently confused with SCXI analog input or signal-conditioning hardware because of its SCXI form factor. That is a serious identification error: the 1193 performs relay-based RF routing, while measurement modules perform signal conversion or conditioning.
Typical Applications
- RF automated test equipment — Routes test signals between instruments and devices under test.
- High-frequency signal multiplexing — Selects one of multiple RF channels for a measurement instrument.
- Sparse RF matrices — Custom relay combinations can create switching arrangements beyond the standard multiplexer configurations.
- PXI/SCXI mixed test systems — NI specifically designed the 1193 for integration with high-frequency PXI instruments.
Technical Pitfalls to Avoid
- Do not identify SCXI-1193 as an 8-channel analog input module. NI’s own product documentation defines it as a 32-channel RF multiplexer switch module.
- Do not overlook the 50 Ω requirement. RF performance depends on maintaining the intended impedance and minimizing unwanted stubs and unused relay paths. NI specifically discusses reducing stub effects when configuring the module for high-frequency operation.
- Topology matters. The same hardware can be configured as 8×1, 16×1, 32×1, or custom sparse-matrix arrangements. A replacement should therefore be tested with the actual NI-SWITCH topology used by the application.
- Relay wear is a real consideration. NI specifies mechanical relay life around 5 × 10⁷ operations but electrical life around 3 × 10⁵ operations. A heavily cycled used unit should not be judged only by whether its relays still click.
- Software compatibility needs checking. NI’s archived compatibility information lists support within older NI-DAQ/NI-SWITCH environments. A replacement should be tested against the actual legacy driver and application environment before field deployment.
Related Products
- NI PXI-2593 — Related 50 Ω RF switch architecture in PXI, useful when migrating away from the older SCXI platform. NI identifies the PXI-2593 as the newer counterpart in its SCXI obsolescence planning.
- NI PXIe-2593 — PXI Express RF switching alternative for newer test architectures.
- NI SCXI-1190 — 1.3 GHz quad 4×1 RF multiplexer; higher frequency range but different switching architecture.
- NI SCXI-1191 — 4 GHz quad 4×1 RF multiplexer for substantially higher-frequency applications.
- NI SCXI-1192 — 18 GHz 8-SPDT 50 Ω relay module; designed for much higher-frequency switching.
- NI SCXI-1194 — Quad 1×4, 2.5 GHz multiplexer.
- NI SCXI-1195 — Quad 1×4, 5.5 GHz multiplexer.
- NI SCXI-1175 — 196×1 relay multiplexer for high-density switching, but it is not an RF-equivalent replacement.
Procurement Note
⚠️ Obsolete model, limited stock available. NI currently identifies / 776572-93 as discontinued and no longer supported.
For a used or surplus replacement, verify the full part number, connector condition, relay switching history, RF insertion loss, and the exact programmed topology. If the system is being redesigned rather than simply repaired, NI’s own obsolescence documentation points toward the PXI-2593/PXIe-2593 family as the successor path, but that is a platform migration rather than a plug-in SCXI replacement.
