Multichannel Systems nanoZ manual - Manual (Page 31)

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Failure to call this function at regular intervals may result in a buffer overrun error.
Recovery from a buffer overrun requires impedance measurement to be stopped.
This will cause any pending results to be lost. Note that if a buffer overrun error
does occur, the impedance measurement test waveform is still applied to the
currently selected channel until the ʻstopʼ function is called.
getwaveformcaps
Returns information about waveform generation capabilities.
Usage: caps = nanoz(‘getwaveformcaps’, handle);
Arguments: handle – handle to an opened device returned by the open function.
Return value: caps – a Matlab structure with the following fields:
fs_gen: generator sampling frequency, in Hz. Typical value is 83333Hz.
fs_adc: Sampling frequency of the A/D converter. Typical value is 10417Hz.
maxsam: Maximum length of the waveform, in samples.
interpol: List of supported interpolation factors.
Remarks: The nanoZ generates waveforms for impedance measurement and
electroplating with an 8-bit digital to analog converter clocked at a sampling
frequency of 83333Hz. Since this may change in future firmware upgrades, user
applications should not rely on the values quoted in the specifications, but rather
query the attached device for its actual capabilities (fs_gen parameter).
Sampling of the analog signal on the electrode is a fraction of the generator
sampling frequency, in this case 1/4, which also may be changed in the future.
The user program should rely on the fs_adc parameter of the caps structure.
Waveforms must be uploaded into the memory of the nanoZ's microcontroller.
The current version has memory for waveforms up to 126 samples (bytes) long.
The minimum frequency that can be generated with a sampling frequency of
83333Hz and 126 samples is approximately 661Hz. Waveform interpolation is
used to generate lower frequencies. The interpol field of the caps structure lists
supported interpolation factors. Linear interpolation is used for factors of 8 or
less. 16x and higher interpolation is performed by 8x linear interpolation
combined with 2x or higher ratio hold interpolation, which effectively reduces the
generator sample rate. Using the maximum 1024x interpolation factor (8x linear +
128x hold), frequencies down to 0.645Hz can be generated.