Data Translation DT3000 Series, Руководство пользователя, Страница: 104 / 156

Supported Device Driver Capabilities
103
Gate-Rising Edge Type
SupportsGateRising
Interrupt-Driven Operations
SupportsInterrupt Yes
a. You can use one-shot mode only with a software gate type (none).
b. You cannot use a software gate type (none) with repetitive one-shot mode
c. In rate generation mode, you can use a duty cycle of 50% or 100% only. If you use a duty cycle of
50%, the output of the specified C/T subsystem is a square wave with a 50% duty cycle. The
frequency of this square wave is determined differently depending on the clock source.
If you use a duty cycle of 100%, the output of the specified C/T subsystem is a square wave that
is low (active) for a specified period, determined by the clock source. If you use an internal clock,
the active period is typically 100 ns; however, for slower frequencies the period may increase to
as much as 1.6
μ
s. If you use an external clock, the active period is 1/external clock frequency.
The remainder of the period is 1/(external clock frequency/external clock divider).
d. In one-shot and repetitive one-shot mode, you can use a duty cycle of 100% only. The output of
the specified C/T subsystem goes low (active) for a period of 1/clock frequency, then goes high
(inactive) for the remainder of the period, which is determined by the gate signal (for repetitive
one-shot operations). The clock frequency depends on the clock source.
e. You cannot use a level gate type with one-shot or repetitive one-shot mode.
f. You can use an edge gate type only with one-shot and repetitive one-shot mode.
Table 20: DT3000 Series Counter/Timer Options (cont.)
DT3000 Series A/D D/A DIN DOUT C/T QUAD
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