Eight analog input channels adapt to a wide range of measurement types and applications. Each channel can be independently pro¬grammed for a thermocouple or voltage measurement. Programmed as a voltage channel you can select one of twelve measurement ranges from ±10 mV to ±50 V. A range of ±5 V supports 4-20 mA measurements using typically a 250 Ω shunt resistor (model R250 sold separately). Pro-grammed as a thermocouple channel you can select from eight thermocouple types: J, K, T, B, R, S, E, or N. Linearization and junction compensation are automatically applied by the DI-2008 for the selected TC type to deliver values scaled in either °C or °F. Rounding out the DI-2008, a built-in 15 V sensor excitation power supply simplifies external wiring and further reduces overall system cost. Finally, all analog measurements benefit from a 16-bit ADC resolution to reveal even the smallest signal variations.
Virtually any measurement will experience a difference in ground potential between the instrument, the signal source, and even between signal sources. Known as common mode voltages, they cause noisy measurements in the best case or damage to the instrument in the worst case unless it’s specifically designed to tolerate them like the DI-2008. Each DI-2008 analog input is electrically isolated from other channels and from ground for safe and accurate measurements in the presence of common mode voltages. Channel isolation means that each analog input is free to float to an independent common mode voltage imposed upon it by the signal source up to 120 V rms, and still provide an accurate and noise-free measurement.
Digital Port Subsystem:
The DI-2008 provides 7 digital ports, each configurable as an input or a switch. Input protection is provided to 30 V. Configured as a switch a digital port can be used to control external loads up to 30 V @ 100 mA, and the switch can be controlled asynchronously without inter-rupting the scanning process. When activated as inputs two ports allow dual functionality to be used as discrete inputs, or one as a counter and the other a rate input. The rate input features a 50 kHz maximum measurement allocated over twelve programmable measure¬ment ranges (10 Hz to 50 kHz full scale). The counter input provides 16-bit resolution and a terminal count value of 65,535. The discrete, counter, and rate inputs are members of the same internal scan list used by the analog input channels. This means that all enabled elements are ac-quired synchronously, which allows meaningful comparisons between analog and digital channels. For example, the rate input mea¬suring engine speed allows rpm data to be acquired synchronously with analog data.
Supports ChannelStretch™ Channel Expansion:
Simply add more DI-2008s to achieve synchronous channel expansion up to 128 analog channels and 112 digital ports (details inside).
- Includes DI-2008 instrument, WinDaq software, calibration certificate, terminal screwdriver, and USB cable (6-feet)
- Eight differential and isolated analog input channels
- Seven bi-directional digital input ports, including:
- Counter input for totalizing applications
- Rate input for frequency/flow/rpm applications
- ChannelStretch™ channel expansion to 128 analog and 112 digital channels
- Programmable voltage and thermocouple measurements per channel
- 10 mV to 50 V programmable range per channel in 12 steps
- Programmable support for type J, K, T, B, R, S, E, N thermocouples per channel
- High resolution (16-bit) measurements
- 2000 Hz max sample throughput for a single channel and 200 Hz for two or more
- Minimum sample throughput rates as low as 1 sample per day
- USB interface
- Included WinDaq software for ready-to-run measurements
- Included .NET class for Visual Studio program development
- Fully documented device protocol supports other operating systems