OMEGA INET-100HC Offers

instruNet provides tens of microvolts of absolute accuracy instead of tens of millivolts, at the same cost and at the same throughput rates as typical general purpose data acquisition boards. It does this with a completely different topology in which the analog electronics are close to the sensor in electrically quiet boxes outside the PC, and noisy digital electronics are left inside.

The external boxes contain signal conditioning amplifiers for each channel and can attach directly to sensors such as thermocouples, thermistors, RTDs, strain gages, load cells, resistance sources, current sources, and voltage sources. The box returns engineering units to the PC (e.g., °C, volts, amps).

At the heart of the real-time system is a PCI card (WIN XP/VISTA (32-bit)/7 (32-bit), PC-card (WIN XP/VISTA (32-bit)/7 (32-bit) or USB 2.0 (WIN XP SP2/VISTA 32-bit or 64-bit/7 32-bit or 64-bit) controller that attaches to a Windows computer. Each controller contains a 32-bit microprocessor with 256 KB of RAM that manages the external “network” of devices.

All real-time tasks are off-loaded to this processor so that the host computer is not burdened with real-time issues. Each instruNet iNET-100 box provides 16 single-ended/8 differential analog inputs, 8 analog outputs, and 8 digital I/O lines.

The iNET-100 includes 44 screw terminals. The iNET-100B version adds 16 BNCs for analog inputs. The controllers themselves have 10 counter/timer channels, each of which can function as a digital input bit, a digital output bit, a clock output channel, a pulse counter, a frequency counter, a period measurement input, or a quadrature counter.

The instruNet system is ideally suited for distributed measurement and control systems. The network cable can extend up to 1000' (304.8 m). Each controller card in the PC can connect to up to 8 instruNet boxes for a total of 128 analog inputs, 64 analog outputs, and 64 digital I/O.

For additional inputs, multiple controller cards can be placed in one computer, with the maximum number of controller cards limited only by the number of available slots. Since each controller card has its own microprocessor, multiple cards do not place any additional burden on the computer.

Each channel can be independently digitally filtered with low-pass, high-pass, band-stop and band-pass filters; the filter specification for each channel is independently set in software. Each channel provides a programmable analog low-pass filter with programmable A/D measurement integration time.

The network can be hundreds of feet long and can support multiple hardware devices connected in a daisy-chain configuration. The start of digitizing can be triggered from any channel.

There are no jumpers or pots; the system automatically self-calibrates on power-up. Because instruNet is modular, it can easily be expanded as needs evolve. One can easily move the system hardware from one computer family to another, since the various controllers are functionally identical.

The iNET-100HC is similar to the iNET-100, yet the voltage output channels have a higher drive capability, providing up to 15 mA of current to capacitive loads as high as 0.01 µF. The iNET-100HC is recommended for use with sensors such as strain gages, RTDs, and thermistors, since these sensors may exceed the current or capacitive drive limits of the iNET-100 or iNET-100B.

The iNET-100HC, furthermore, provides greater compatibility with sensors that have capacitive loading on the excitation lines, therefore it is recommended for all sensors requiring excitation, including RTDs and thermistors. Since the HC version has a greater power demand, an external power supply must be used.

Features

• High-accuracy data acquisition for Windows computers
• 16 single-ended/8 differential 14-bit analog inputs, 8 analog outputs, and 8 digital I/O
• iNET-240 USB 2.0 controller
• Direct connection to RTD, thermocouple, voltage, current, accelerometer, potentiometer, load cell, thermistor, bridge, and strain gage sensors
• Each channel has independently programmable analog and digital filters, integration time, voltage range, and sample rate
• 166 KS/s throughput to RAM or disk
• Includes strip chart software and drivers for C, Visual Basic.Net, and TestPoint
• Optional LabVIEW drivers are available
• Optional DASYLab software includes iNET drivers for easy-to-use, icon-based programming

Applications

• Multichannel thermocouple and RTD temperature measurement in a Windows-based test setup
• Strain gage and load cell measurement for structural and mechanical testing
• Distributed measurement and control across a daisy-chained sensor network up to 1000' (304.8 m)
• Continuous waveform digitizing and spooling to disk for long-duration data logging
• Real-time PID and on/off feedback control of analog and digital output channels