Data Translation DT300 Series, User Manual

Page: 103 / 164

Principles of Operation
103
Figure 40: Example of Rate Generation Mode with a 25% Duty Cycle
One-Shot
Use one-shot mode to generate a single pulse output signal from the counter when the
operation is triggered (determined by the gate input signal). You can use this pulse output
signal as an external digital (TTL) trigger to start other operations, such as analog input or an
external instrument.
When the one-shot operation is triggered and a single pulse is output; then, the one-shot
operation stops. All subsequent clock input signals and gate input signals are ignored.
The period of the output pulse is determined by the clock input signal. Refer to page 95 for
more information on the C/T clock sources.
Using software, specify the counter/timer mode as one-shot, the clock source, the polarity of
the output pulse (high-to-low transition or low-to-high transition), and the gate type to trigger
the operation. Refer to
page 97 for more information on pulse output types. Refer to page 96
for more information on gate types.
Note: In the case of a one-shot operation, the pulse width is automatically set to 100%.
Ensure that the signals are wired appropriately. Figure 41 shows one example of connecting a
pulse output operation to the STP300 screw terminal panel using user counter 0.
Pulse
Output
Signal
25% duty cycle
Continuous Pulse
Output Operation Starts
External C/T
Clock
Input Signal
(4 kHz)