VTI Instruments EX1401, Руководство пользователя

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EX1401 Introduction 15
An onboard, web-accessible user interface allows you to instantly verify communications and
instrument functionality, while IVI drivers provide a familiar application programming interface to
further reduce integration and program development time. For comprehensive, programming-free
data recording setup, management and viewing, use EX1401 instruments with one of VTI’s full-
featured, turnkey software solutions, such as EXLab.
Channel Independence
Each of the EX1401’s 16 differential input channels is an independent signal conditioning path,
complete with amplification and continuous open transducer detection. This independence frees the
user from the problem of channel-to-channel crosstalk that is pervasive in most multi-channel data
acquisition systems. In the EX1401, channels have no influence on each other, regardless of
scanning speed or channel state. Specifically, open or significantly overloaded channels do not affect
the measurement results of any other channels.
Custom Thermocouple support
When configured in thermocouple mode, each input can be individually configured to support
specific type of thermocouple. In addition to supporting standard thermocouple types (J, K, T, E, S,
R, B and N), the EX1401 can also support custom thermocouple types (e.g., C-Type) through the
input of user-defined thermocouple polynomial coefficients. Each of the EX1401’s channels can be
configured with a unique custom 12
th
order polynomial for both voltage-to-temperature and
temperature-to-voltage conversions.
Analog Filter
Each EX1401 input channel has a fixed, 2-pole, 30kHz low pass filter with an RC response
providing anti-alias filtering. The analog signals after the anti-alias filter are over sampled at 320kHz
to 640kHz by the ADCs. This combination of anti-alias filter with ADC oversampling provides
60dB of rejection at the aliasing band.
Digital Filter
The EX1401 allows the user to configure different types of digital filters per channel. These digital
filters are implemented inside the FPGA of the device, such that they perform consistently and
without loading the host computer resources. Users can optimize the filter settings for aggressive
filter performance or lower data latency time. In addition, users can customize the FIR filter
performance by editing the coefficients of the filter. This provides ultimate flexibility in designing
a filter to suit the application needs.
Input Connectors
The EX1401 employs uncompensated (Cu-Cu) mini-thermocouple female jacks as an input
connector. This connector provides a solid, reliable connection that is also easily changeable. Since
it is not thermocouple-type specific, different thermocouple types can be mixed throughout the unit
without hardware modification.
Sampling Rate
The EX1401 is designed for sampling speeds up to a 20 kSa/s per channel, regardless of the number
of enabled channels. The lowest sampling speed is 0.000002328 Hz (approximately one sample
every 5 days.)
Digital I/O and Limits
The EX1401 allows the users to define a unique set of programmable limits that are used for open
transducer detection as well as general purpose input channel monitoring. These limits are
programmable on a per channel basis and are evaluated, within the instrument with each completed