Field Application Notes; Dac Code Change Glitch; Output Status When Changing Range - Advantech iDAQ-817 User Manual

3.5

Field Application Notes

Here are some notes related to field applications. They are mainly about the consid-
erations of safety, especially the output function in some machine-controlling scenar-
ios.
3.5.1

DAC Code Change Glitch

When the output voltage or current of an analog output channel changes, glitches
may be observed. This is a normal phenomenon due to released charges of the
DAC. The largest glitches occur when the most significant bit of the DAC code
changes.
To preserve the slew rate and settling time specifications, no further signal condition-
ing is applied in the device. If the glitches are unacceptable, an external low-pass
deglitching filter can be used to reduce the glitches. However, users should verify that
the frequency response and distortion of the signal due to the deglitching filter can
still meet the requirement of the applications.
3.5.2

Output Status When Changing Range

When analog output range changes, the output voltage or current will reset to 0 and
stay until another software command changes it. This prevents unexpected voltage
or current change when changing output range.
iDAQ-817_821 User Manual
Figure 3.10 Device description shown in Navigator
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