INET-100HC instruNet Series Direct Sensor to Data Acquisition

Supported Applications

The Omega instruNet Series is a direct sensor-to-data acquisition system designed for high-accuracy data collection on Windows computers. The architecture places analog electronics in electrically quiet external boxes near sensors while retaining digital processing within the PC, supporting laboratory and factory equipment interfacing. The series supports a wide range of measurement types including thermocouples (J, K, T, E, R, S, B, N, C, D, G), RTDs (100 Ω, 500 Ω, 1000 Ω), thermistors, strain gages, voltage, current, and resistance sources. Applications include real-time monitoring, data logging, and analysis via instruNet World software or optional drivers for LabVIEW.

Operating Conditions & Performance

The system provides 16 single-ended/8 differential analog inputs with 14-bit resolution and a minimum A/D conversion time of 4 μs. System throughput reaches up to 166K samples/s, though multiple boxes on a network may degrade this maximum rate. Voltage input ranges include ±5V (±700 μV accuracy), ±0.6V (±75 μV), ±80 mV* (±15 μV), and ±10 mV* (±10 μV). Thermocouple accuracies vary by type and range; for example, Type K offers ±0.8°C from -200 to -50°C and ±0.6°C from -50 to 1372°C. RTD accuracy ranges include ±0.37°C for a 100 Ω sensor (0 to 200°C) with a 1 kΩ shunt, improving to ±1.0°C at higher temperatures.

Analog outputs provide 8 channels with 8-bit resolution and an output range of ±5V @ 5 mA for iNET-100/100B models or ±5V @ 15 mA for the iNET-100HC. Digital I/O consists of 8 non-latching inputs and 8 latching outputs at bidirectional screw terminals, with input levels from -200 μA to +3.2V min.

Key Performance Metrics

• Analog Inputs: 16 single-ended/8 differential; Input Impedance >22 MΩ, 3pf; Common-Mode Voltage ±5V min (CMR ±80 dB).
• Voltage Accuracy: Ranges from ±700 μV to ±10 μV depending on integration time and range.
• Thermocouple Support: Includes J, K, T, E, R, S, B, N, C, D, G types with specific accuracy per temperature band.
• Digital I/O Levels: Input V_ = 3.2V min to 12V max; Output I° = 50 mA max at 0.7V.

Configuration Options

The instruNet Series is configurable across multiple dimensions including sensor interface, controller type, and expansion options. The core network devices include the iNET-100 (screw terminals), iNET-100B (adds 16 BNC connectors for voltage inputs), and iNET-100HC (provides 15 mA excitation current per channel). Controllers enable connection to desktop or laptop PCs via USB 2.0 (iNET-240) or PCI-Bus (iNET-200, controls up to 8 boxes).

Available Options and Accessories

• Power Solutions: iNET-312-8 (USA plug) or iNET-312-8EU (Euro plug); required for networks exceeding two standard boxes.
• Isolation & Mounting: iNET-330 Optical Isolator; iNET-340 DIN Rail Mounting Brackets.
• Cabling: Network cables available in 10FT, 25FT, 50FT, and 100FT lengths (up to 30.5 m).
• Software & Drivers: iNET-IWPLUS license; LabVIEW drivers (versions 4–6 supported); DASYLab compatibility.
• Precision Shunts: OMX-R250, OMX-R1K, OMX-R4.7K, OMX-R47K for current measurement applications.

Network Expansion

A single network can extend up to 304.8 m (1000') and support up to 128 analog inputs, 64 analog outputs, and 64 digital I/O lines when multiple boxes are daisy-chained. Each controller operates independently, allowing installation of as many controllers as space permits.

Key Product Differences

The series distinguishes models by interface type, drive capability, and connectivity method:

• iNET-100 vs. iNET-100B: The base model uses screw terminals; the B variant adds 16 additional BNC connectors for voltage inputs.
• iNET-100HC: Identical to iNET-100 but provides higher drive capability (15 mA excitation current per channel) compared to standard models.
• Controller Types: The iNET-240 uses USB 2.0 for Windows XP/Vista/7 systems; the iNET-200 is a PCI-Bus card compatible with similar OS versions and supports up to eight network devices per controller.