Data Translation DT9812 Series, User Manual

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Chapter 5
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For example, if the software returns a code of 3072 for the analog input operation, determine
the analog input voltage as follows:
Voltage = (2.44 * 3072) / 4096 = 1.83 V
Converting a Twos Complement Code to a Voltage
To convert a twos complement code into a voltage on the DT9812-10V, DT9812-10V-OEM,
DT9812A, DT9813-10V, DT9813A, DT9814-10V, or DT9814A module, use the following
formula:
Voltage = (20 * Code) / 4096
where,
• 20 is the full-scale range of the module (-10V to +10V)
• Code is the raw count used by the software to represent the voltage
• 4096 is the input resolution (12 bits)
• Voltage is the analog voltage
For example, assume that the software returns a code of 1040 for the analog input value.
Determine the analog input voltage as follows:
Voltage = (20 * 1040) /4096 = 5.078 V
Error Conditions
An overrun condition is reported if the A/D sample clock rate is too fast. This error is reported
if a new A/D sample clock pulse occurs while the ADC is busy performing a conversion from
the previous A/D sample clock pulse. It is up to the host application to handle this error by
either ignoring the error or stopping acquisition. To avoid this error, use a slower sampling
rate or increase the buffer size and/or number of buffers.