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PicoScope 2104 & 2105 PC Oscilloscope User Guide
3.4.7AC/DC operation
Using the ps2000_set_channel() function, the input can be set to either AC or DC coupling. When AC coupling is used, any DC component of the signal is filtered out.
3.4.8Oversampling
When the unit is operating in block mode at speeds less than the maximum, it is possible to oversample, which means taking more than one measurement during a time interval and returning an average. This reduces the effects of noise, and increases the effective vertical resolution of the oscilloscope.
Setting an oversampling factor of n increases the time interval by a factor of n and reduces the maximum number of samples by the same factor. At the same time it increases the effective resolution by the amount given by the equation:
increase in resolution (bits) = ( log oversample ) / ( 2 log 2 )
For example, an oversampling factor of four increases the resolution by one bit.
The ps2000_run_block() function controls oversampling.
3.4.9Scaling
PicoScope 2000 Series PC Oscilloscopes have a resolution of 8 bits, but the oscilloscope driver normalises all readings to 16 bits. This enables it to take advantage of noise reduction from oversampling, when this is enabled. The following table shows the relationship between the reading from the driver and the voltage of the signal.
Reading | Voltage |
Negative full scale | |
0 | Zero volts |
32 767 | Positive full scale |
Copyright 2006 Pico Technology Limited. All rights reserved. |
