Chapter 4
Analog Input
4-32
ni.com
Using an Internal Source
One of the following internal signals can drive ai/ConvertClock:
•
AI Convert Clock Timebase (divided down)
•
Counter
n
Internal Output
A programmable internal counter divides down the AI Convert Clock
Timebase to generate ai/ConvertClock. The counter is started by
ai/SampleClock and continues to count down to zero, produces an
ai/ConvertClock, reloads itself, and repeats the process until the sample is
finished. It then reloads itself in preparation for the next ai/SampleClock
pulse.
Using an External Source
Use one of the following external signals as the source of ai/ConvertClock:
•
PFI <0..15>
•
RTSI <0..7>
•
PXI_STAR
•
Analog Comparison Event (an analog trigger)
Routing AI Convert Clock Signal to an Output
Terminal
You can route ai/ConvertClock (as an active low signal) out to any
PFI <0..15> or RTSI <0..7> terminal.
All PFI terminals are configured as inputs by default.
Using a Delay from Sample Clock to Convert Clock
When using an internally generated ai/ConvertClock, you also can specify
a configurable delay from ai/SampleClock to the first ai/ConvertClock
pulse within the sample. By default, this delay is three ticks of
ai/ConvertClockTimebase.