Measurement Computing Data Translation DT3034 User Manual page 99

Chapter 6
Through software, specify the clock source as internal and the frequency at which to pace the
counter/timer operation (this is the frequency of the clock output signal). The maximum
frequency that you can specify for the clock output signal is 10 MHz. For a 32-bit cascaded
counter, the minimum frequency that you can specify for the clock output signal is 0.00465
Hz, which corresponds to a rate of once every 215 seconds.
Note: In software, specify the clock input and gate input for the first counter in the cascaded
pair. For example, if counters 1 and 2 are cascaded, specify the clock input and gate input for
counter 1.
Gate Types
The active edge or level of the gate input to the counter enables counter/timer operations. The
operation starts when the clock input signal is received. DT3034 boards provide the following
gate input types:
• None – A software command enables any specified counter/timer operation immediately
• Logic-low level external gate input – Enables a counter/timer operation when the
• Logic-high level external gate input – Enables a counter/timer operation when the
• Falling-edge external gate input – Enables a counter/timer operation on the transition
• Rising-edge external gate input – Enables a counter/timer operation on the transition
Specify that gate type in software.
Table 6
counter/timer.
98
after execution. This gate type is useful for all counter/timer modes.
external gate signal is low, and disables the counter/timer operation when the external
gate signal is high. Note that this gate type is used only for event counting, frequency
measurement, and rate generation; refer to
external gate signal is high, and disables a counter/timer operation when the external
gate signal is low. Note that this gate type is used only for event counting, frequency
measurement, and rate generation; refer to
from the high level to the low level (falling edge). In software, this is called a low-edge
gate type. Note that this gate type is used only for one-shot and repetitive one-shot mode;
refer to page 107 for information on these modes.
from the low level to the high level (rising edge). In software, this is called a high-edge
gate type. Note that this gate type is used only for one-shot and repetitive one-shot mode;
refer to page 107 for information on these modes.
lists the screw terminals that correspond to the gate input signals of each
page 100 for more information on these modes.
page 100 for more information on these modes.