The National Instruments NI 9216, part number 157270B-01L, is an eight channel RTD input module for CompactDAQ and CompactRIO systems. It provides 24 bit resolution and is designed for temperature measurement with resistance temperature detectors. The module is used in industrial monitoring, laboratory testing, thermal validation, and process control applications where stable and accurate temperature data is required.

RTDs provide stable and repeatable temperature measurement over a defined range. The NI 9216 brings RTD input capability to the C Series platform. Engineers can connect RTD sensors directly to a CompactDAQ or CompactRIO chassis and acquire temperature data alongside other measurements in the same system.

Eight RTD Input Channels

The module provides eight RTD input channels. Each channel can be configured for the RTD type and wiring configuration required by the application. Engineers should verify sensor type, temperature range, and lead configuration before wiring.

RTD wiring should use appropriate lead compensation for the selected configuration. Two wire, three wire, and four wire connections differ in their ability to cancel lead resistance, so the choice affects achievable accuracy. Proper labeling of channels helps maintenance and troubleshooting.

Resolution and Measurement Accuracy

The NI 9216 uses 24 bit analog to digital conversion. High resolution supports fine temperature measurement and detection of small changes. Engineers should verify accuracy requirements and calibration status for the application.

Low level resistance measurements require careful wiring and grounding. Shielded cable and separation from high current conductors reduce noise. Sensor self heating should be considered where excitation current and thermal mass interact.

CompactDAQ and CompactRIO Integration

The NI 9216 is a C Series module and operates in compatible CompactDAQ and CompactRIO systems. In CompactDAQ, it provides RTD input for USB or Ethernet based measurement systems. In CompactRIO, it supports embedded monitoring and control applications that require temperature input.

The module can be combined with thermocouple, voltage, and digital modules for mixed measurement systems. Software configuration allows channels to be scaled to engineering units and logged together.

Applications

The module is suited to thermal chamber monitoring, industrial process monitoring, energy systems, and product validation. It supports accurate temperature measurement in a compact chassis and can be expanded with additional modules when more channels are needed.

Installation and Maintenance

Installation requires inserting the module into a compatible C Series slot and connecting RTD wiring according to the product documentation. Channels should be labeled and wiring secured. The chassis should provide adequate cooling and protection.

Maintenance includes checking terminals, verifying sensor integrity, and confirming calibration. Documentation of sensor types and channel assignments helps maintain repeatability.

Summary

The National Instruments NI 9216 Analog Input Module provides eight RTD channels with 24 bit resolution for CompactDAQ and CompactRIO systems. It supports accurate temperature measurement and thermal testing. The NI 9216 is a practical choice for engineers who need dense RTD input in a modular platform.