rtd DM6210, Руководство пользователя

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5-4
• Reading the Converted Data
The converted data is read from the register at BA + 0. This is a 16-bit register with the A/D data in the upper
12 bits. The bottom 4 bits have no meaning and should be diregarded.
To convert the data to a voltage value, you must scale the digital value properly. First you must shift the
data right 4 places. This can be done by either using a shift right command or by dividing the value by 16.
Once the data is shifted, it must be multiplied by a scaling factor to convert the value to a voltage. This
scaling factor will change depending on the input range you have selected and the gain you have installed in
the resistor configurable gain. The formulas for calculating voltage are shown below.
+/- 5 volt range:
(A/D Value - 2048) bits * (10 volts / 4096 bits) = input volts
For example, if the A/D reading is 1024, the analog input voltage is calculated as follows:
(1024 - 2048) bits * 2.4414 mV/bit = -2.5 volts.
+/- 10 volt range:
(A/D Value - 2048) bits * (20 volts / 4096 bits) = input volts
For example, if the A/D reading is 1024, the analog input voltage is calculated as follows:
(1024 - 2048) bits * 4.8828 mV/bit = -5.0 volts.
0 to +10 volt range:
(A/D Value) bits * (10 volts / 4096 bits) = input volts
For example, if the A/D reading is 1024, the analog input voltage is calculated as follows:
(1024) bits * 2.4414 mV/bit = +2.5 volts.
The key digital codes and their input voltage values are given in the following table.
' ' ' ' ' ' ' ' ' ' ' ' ' ' ' '
%LW %LW %LW %LW %LW %LW %LW %LW %LW %LW %LW %LW ; ; ; ;