Somat eDAQlite, Руководство пользователя

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Somat eDAQ
lite
96 I2773-4.
4
en
Figure 5-6: Diagram of the 37-pin D-Sub connector on an ELNTB layer.
Each channel uses a notched filter processor that generates about seven samples per
second. Since these channels are not isolated from each other, they can only be used
in applications where the individual thermocouples are electrically isolated from each
other. A cold junction box is required for each bank and is connected to the eDAQ
lite
with the cables provided using the connectors labeled “A01-A16” or “B01-B16” located
on the front panel. Each thermocouple is connected to the miniature barrier strip type
paired inputs in the junction box.
NOTE
Thermocouple leads should not exceed 30 meters in length from connector to tip.
The eDAQ
lite
uses the industry standard software compensation algorithm to
generate the temperature data samples. The eDAQ lite first measures the
cold-junction compensation (CJC) temperature and converts it to the equivalent
microvolt value using a high-resolution lookup table. The eDAQ
lite then subtracts the
CJC equivalent microvolt value from the thermocouple’s output microvolt value. The
temperature is found using another high-resolution lookup table. The lookups are
based on the ITS-90 Thermocouple Direct and Inverse Polynomials.
For more information on setting up ELNTB input channels, see
“Thermocouple” on
page 121 .
Application Note on Measuring Differential Temperatures
To measure differential temperatures using the ELNTB layer, select two or more adjacent channels on the same bank. Use
matched thermocouples for optimum differential accuracy.
Due to instrumentation noise, it is recommended that the maximum sample rate (e.g., 5 Hz for the 100 KHz MSR option) and
a Smoothing Filter computed channel be used for each input channel. Using a five- or seven-tap Smoothing Filter typically
reduces the instrumentation noise to below 0.2° C peak to peak (for all thermocouple types). Using more taps can further
reduce the noise.
To generate the differential temperature, use a simple Desk Calculator computed channel. Use a Down Sampler computed
channel to achieve the desired data storage rate.
5.7 EGPS-5HZ (Somat GPS Receiver)
The EGPS-5HZ is a commercial WAAS-enabled GPS receiver with a fixed 5 Hz
navigational update rate. The receiver continuously tracks and uses up to 12 satellites
to compute and update position. The receiver has a serial interface connection routed
to the ELDIO or ELCOM.
Another feature available with the EGPS-5HZ receiver is GPS-based master sample
rate clock generation. Use the configuration options of the parent layer (ELDIO or
ELCOM) to enable GPS clock generation.
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