I. Product Introduction

The NI SCXI-1308 is a 32-channel current input terminal board, not a data acquisition module, specifically designed for the SCXI-1100, SCXI-1102/B/C high-precision analog input modules. The core feature is that each channel is equipped with a 249Ω precision resistor, which is used to convert 0–20mA / 4–20mA industrial current signals into voltage signals for the subsequent modules to collect; it is fully metal shielded and has screw terminals, suitable for high-channel-count industrial current measurement. It is now discontinued (Obsolete), and spare parts and maintenance are available.

II. Model and Component Number

Model: SCXI-1308

Location: Special terminal board for high-channel current input on the SCXI platform, compatible with the 1100/1102 series

III. Technical Parameters

Electrical Parameters

Channels: 32 differential current input

Conversion Resistance: 249Ω, 0.1% accuracy, 10ppm/℃ temperature drift, 1/4W

Input Current Range: 0–20mA, 4–20mA

Conversion Voltage: 4–20mA → 1–5V; 0–20mA → 0–5V

Rated Voltage:

Between channels: 30Vrms / 42.4Vpeak / 60VDC

To ground of each channel: 30Vrms / 42.4Vpeak / 60VDC

Input protection: Voltage limiting for each channel, protection against overcurrent / overvoltage

Connectors: 78 screw terminals (32 pairs of differential + ground + reserved)

Mechanical and environmental

Installation: Standard SCXI front panel, direct-insert module 96-pin DIN connector

Size: Standard SCXI size (same as 1304/1305 series)

Weight: Approximately 450g

Temperature: Operating 0–50℃; Storage - 20–70℃

Humidity: 10%–90% RH, no condensation

Shielding: Full metal shielding enclosure, anti-EMI/RFI

Four. Interfaces and Configuration

Front panel: 78 screw terminals (32× differential ±, ground, SCXIbus Guard, reserved)

Backplane: 96-pin DIN connector, direct connection to SCXI-1100/1102 front end

Configuration: No jumpers / No software configuration, resistors fixed, plug-and-play

Software: Compatible with NI-DAQmx, supports LabVIEW, C/C++, LabWindows/CVI

Five. Core Functions

32-channel current to voltage: 249Ω precision resistor, precise conversion of 4–20mA / 0–20mA industrial standard current signals.

High channel density: 32 differential pairs on a single terminal board, compatible with SCXI-1102/B/C (32 channels), builds high-density current acquisition system.

Industrial-grade anti-interference: Full metal shielding + screw terminal stress release, anti-vibration, anti-loosening, suitable for factory strong interference environment.

Plug-and-play: No hardware jumpers, no software configuration, direct acquisition after power failure, simplifies deployment.

Six. Application Scenarios

Industrial process control: 4–20mA transmitters (pressure, temperature, flow, level) signal acquisition.

High-channel current measurement: 32 synchronous acquisition, compatible with SCXI-1102/B/C.

SCXI-1100/1102 companion: Combined with 1100 (16 channels), 1102/B/C (32 channels).

Strong interference factory environment: Near motors, frequency converters, shielding + overvoltage protection ensures stability.

Seven. Use and Maintenance Use

Power-off installation: Align and push into the 1100/1102 front end, lock the 96-pin connector, and fix the screws.

Wiring: Positive current source - Connect to channel +, negative current source - Connect to channel -. Shielded wire is connected to the ground to reduce common-mode interference.

Software: Select the module in NI-DAQmx, set the voltage range (±5V), and directly read the converted voltage. Maintenance

Environment: 0 - 50℃, dry and ventilated, away from strong electromagnetic interference.

Check: Regularly inspect for loose screws and oxidation of terminals. Tighten and clean.

Cleaning: Disconnect power, wipe terminals with anhydrous alcohol, then power on after drying.

Storage: Disconnect power, remove the board, seal with an anti-static bag, and store in a cool and dry place.