Description
1. Detailed Parameter Table
| Parameter Name | Parameter Value |
| Product Model | SCXI-1349 |
| Manufacturer | National Instruments (NI) |
| Product Category | Terminal Block for SCXI Modules |
| Compatible Modules | SCXI-1125, SCXI-1126, SCXI-1127, SCXI-1140, SCXI-1141 |
| Connector Type | 68-pin VHDCI (female) on module side; screw terminals (32 channels) on field side |
| Channel Configuration | 32 single-ended channels or 16 differential channels |
| Maximum Voltage Rating | 300 V CAT II |
| Maximum Current per Channel | 1 A |
| Isolation Rating | 250 Vrms (channel-to-channel, channel-to-ground) |
| Physical Dimensions | 16.5 cm x 10.2 cm x 3.8 cm (length x width x height) |
| Weight | 0.4 kg |
| Operating Temperature Range | 0 °C to 55 °C |
| Material | Polycarbonate housing, nickel-plated brass connectors |
NI SCXI-1349
2. Product Introduction
The NI SCXI-1349 is a high-density terminal block designed to provide a secure, user-friendly interface between field devices and compatible SCXI signal conditioning modules. As part of NI’s SCXI accessory lineup, it simplifies wiring in data acquisition systems by converting the 68-pin VHDCI connector of SCXI modules into easily accessible screw terminals.
Ideal for industrial and laboratory environments, the NI SCXI-1349 supports both single-ended (32 channels) and differential (16 channels) configurations, making it adaptable to various signal types and noise environments. By serving as the physical bridge between sensors/actuators and SCXI modules, the NI SCXI-1349 ensures reliable signal transmission while simplifying system setup and maintenance. In automation systems, this terminal block enhances safety and reduces wiring errors, particularly in applications involving multiple analog signals.
3. Core Advantages and Technical Highlights
Flexible Channel Configuration: The NI SCXI-1349 accommodates 32 single-ended or 16 differential channels, allowing users to optimize wiring based on signal type and noise considerations. This flexibility makes it suitable for mixed-signal systems, such as those combining thermocouples (differential) and proximity sensors (single-ended).
Enhanced Safety and Durability: With a 300 V CAT II rating and 250 Vrms isolation, the NI SCXI-1349 provides robust protection against voltage spikes and ground loops common in industrial environments. Its polycarbonate housing resists chemical exposure and mechanical stress, ensuring long-term reliability in harsh conditions.
Simplified Wiring and Maintenance: The screw terminal design eliminates the need for specialized tools, enabling quick connection of field wires. Each terminal is clearly labeled with channel numbers, reducing wiring errors during installation. This design also facilitates easy reconfiguration or troubleshooting without disconnecting the entire system.
Seamless SCXI Integration: Specifically engineered for compatibility with SCXI-1125, SCXI-1126, SCXI-1127, SCXI-1140, and SCXI-1141 modules, the NI SCXI-1349 ensures optimal signal integrity between the terminal block and conditioning modules. This integration is critical for maintaining measurement accuracy in high-precision applications like aerospace component testing.
4. Typical Application Scenarios
Industrial Process Monitoring: In manufacturing plants, the NI SCXI-1349 connects to SCXI-1125 isolation modules, interfacing with pressure transducers, flow meters, and temperature sensors throughout production lines. Its screw terminals simplify wiring in control cabinets, while differential configuration minimizes noise from nearby motors and machinery.
Aerospace Test Rigs: For aircraft component testing, the NI SCXI-1349 links strain gauges and accelerometers to SCXI-1141 signal conditioners. The terminal block’s isolation features protect sensitive measurement equipment from voltage transients, while its compact size saves space in crowded test enclosures.
Laboratory Research Setups: Academic labs use the NI SCXI-1349 with SCXI-1126 modules to connect various sensors—from pH probes to load cells—in materials science experiments. Its flexible channel configuration allows researchers to reconfigure the system quickly for different test protocols.
Energy Distribution Monitoring: In smart grid applications, the NI SCXI-1349 connects current transformers and voltage sensors to SCXI-1127 modules, facilitating monitoring of power distribution networks. The terminal block’s high voltage rating ensures safe operation in electrical substation environments.
NI SCXI-1349
5. Related Model Recommendations
SCXI-1125: An 8-channel isolated analog input module that pairs with the NI SCXI-1349 to provide galvanic isolation for industrial signals, ideal for noisy environments.
SCXI-1000: A 13-slot SCXI chassis that houses the NI SCXI-1349 and compatible modules, providing power and backplane communication for the signal conditioning system.
PXI-6224: A multifunction DAQ module that works with SCXI systems via the NI SCXI-1349, enabling data acquisition from conditioned signals in PXI-based test setups.
SCXI-1327: A terminal block similar to the NI SCXI-1349 but optimized for thermocouple measurements, featuring cold-junction compensation for temperature sensors.
SHC68-68-EPM: A shielded cable that connects the NI SCXI-1349 to SCXI modules, reducing electromagnetic interference in high-noise environments.
SCXI-1141: A 16-channel differential amplifier module that, when used with the NI SCXI-1349, provides high-gain signal conditioning for low-level sensors like strain gauges.
6. Installation, Commissioning and Maintenance Instructions
Installation Preparation: Before installing the NI SCXI-1349, ensure the SCXI chassis is powered off. Verify compatibility with the target SCXI module (e.g., SCXI-1125). Use appropriate wire gauge (18-24 AWG) for field connections, stripping 6-8 mm of insulation from wire ends. Mount the terminal block securely using the provided brackets to prevent strain on connections during wiring.
Commissioning Steps: Connect the NI SCXI-1349 to the SCXI module using a compatible 68-pin VHDCI cable (e.g., SHC68-68-EPM). Terminate field wires to the screw terminals, ensuring tight connections to prevent signal degradation. Power on the SCXI chassis and launch NI MAX to confirm communication with the module. Perform a signal integrity test by applying known voltages to several channels and verifying measurements match expected values.
Maintenance Suggestions: Inspect the NI SCXI-1349 quarterly for loose terminals or corrosion, especially in humid environments. Retighten screws if necessary using a torque screwdriver (0.5-0.7 N·m) to avoid damaging terminals. Clean the housing with a dry cloth; avoid chemical cleaners that may degrade the polycarbonate. If replacing wires, label connections beforehand to maintain channel mapping accuracy.
7. Service and Guarantee Commitment
NI provides a 1-year standard warranty for the NI SCXI-1349, covering defects in materials and workmanship. During this period, NI will replace faulty terminal blocks at no cost, ensuring minimal disruption to system operation.
The company’s technical support team offers guidance on proper installation, wiring configurations, and compatibility with SCXI modules through online resources and direct consultation. NI also provides detailed documentation, including wiring diagrams and mounting instructions, to facilitate correct setup of the NI SCXI-1349. This commitment to quality ensures users can rely on the terminal block for secure, long-term signal connections in critical data acquisition systems.
