Instructions

UM-0085-B09 DT80 Range User Manual Page 330
RG
 Example
The following example shows how the DT80 might be used to calculate a strain value. It will most likely need to be
adapted to suit the type of sensor and the application. In this case a 5-wire sensor is used, with the manufacturer
supplied parameters as shown.
BEGIN
'Manufacturer data
'b = 68.22 ohm
'a = 4.86 degC/ohm
'G = 5.8962 ue/0.01%
'Z = 1.0137
'C = 10.56 ue/degC
RA12H
1R(ES5,4W) 'measure R1, take 5 extra samples to reduce noise
2R(ES5,4W) 'measure R2, take 5 extra samples to reduce noise
'calculate temperature if required
CALC("Temp~degC")=((&1R+&2R)-68.22)*4.86
'calculate strain
CALC("Strain~ue")= 58962*(&1R/&2R-1.0137)-10.56*Temp
END
So in this case if the measured resistances were R1=36.44 and R2=35.56 then the calculated temperature would be
18.4°C and the strain +457 µε.
Analog Logic State Inputs
For reading logic states, the DT80's digital inputs (see Digital Channels (P331)) are the best option. If there are
insufficient digital inputs then the analog inputs can also function as digital inputs, using the
AS channel type.
The AS channel type detects an input voltage relative to a threshold:
• When the input is above the threshold, 1 is returned
• When the input is below the threshold, 0 is returned
Any of the Voltage wiring configurations may be used.
The default threshold is 2500mV, but the channel factor can be used to set any value in mV.
Input attenuators are enabled by default for the AS channel type, allowing input voltages up to 30V.
For example:
1AS(1750)
configures analog channel 1 as an analog state input with a threshold of 1.75V.