Measurement Computing Data Translation DT3034, Руководство пользователя

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Principles of Operation
99
Pulse Output Types and Duty Cycles
DT3034 boards can output pulses from each counter/timer. Table 7 lists the screw terminals
that correspond to the pulse output signals of each counter/timer.
DT3034 boards support the following pulse output types on the clock output signal:
• High-to-low transitions – The low portion of the total pulse output period is the active
portion of the counter/timer clock output signal.
• Low-to-high transitions – The high portion of the total pulse output period is the active
portion of the counter/timer pulse output signal.
You specify the pulse output type in software.
The duty cycle (or pulse width) indicates the percentage of the total pulse output period that
is active. A duty cycle of 50, then, indicates that half of the total pulse is low and half of the
total pulse output is high. You specify the duty cycle in software.
Figure 29 illustrates a low-to-high pulse with a duty cycle of approximately 30%.
Table 6: Gate Input Signals
Counter/Timer Screw Terminal on the DT740
0 TB60
1 TB64
2 TB68
3 TB72
Table 7: Pulse Output Signals
Counter/Timer Screw Terminal on the DT740
0 TB59
1 TB63
2 TB67
3 TB71