TDT RZ2 Manual page 342

7-28
Signal Resolution
Signal resolution is dependent on the sampling rate used. PCM D/A converters allow
users to generate precise pulsed signals, including square waves with durations of
only 1 sample.
Designing the Stimulus Signal
The stimulator system offers flexible stimulus delivery capable of generating complex
patterns of pulses or arbitrary waveforms. This allows you to make use of the full
range of the waveform and pulse generators in the RPvdsEx component library,
including the PulseGenN macro.
Desired Signal Range
Consider the output range of the system when adding and configuring waveform
components. The IZ2MH stimulator can deliver stimuli in the range of +/- 3 mA.
The IZ2M stimulator can deliver stimuli in the range of +/- 300 μA. Be sure to set
component amplitude parameters with the output range of your device in mind. In the
figure below, the amplitude of a biphasic pulse is defined in the Amp-A and Amp-
B parameters.
When using components that output a logical (TTL) signal, such as a PulseTrain,
the output range can be defined when the output is converted to the desired data
type. In the figure below, the PulseTrain component sends out a TTL signal with a
fixed duration. A TTL2Float component is then used to convert the signal to a user
specified value between 0 and 3000. This floating point value indicates the desired
stimulator output in microAmps. The desired μAmps hop is a multi-channel floating
point signal that can be fed directly to the IZ2_Control macro's StimSignal input
or further manipulated as in the next example.
Setting Multiple Channels for Stimulation
This example generates a 16-channel signal for voltage stimulation. The base
stimulation is a +/-100 μA bipolar pulse generated by the PulseGenN macro. The
StimScales data table holds the scale factors that will be applied to each channel's
stimulus. The output (desired μA) can be connected directly to the StimSignal
IZ2M/IZ2MH Stimulator
System 3