Chapter 4
Analog Input
©
National Instruments Corporation
4-17
Using an Internal Source
One of the following internal signals can drive AI Convert Clock:
•
AI Convert Clock Timebase (divided down)
•
Counter
n
Internal Output
A programmable internal counter divides down the AI Convert Clock
Timebase to generate AI Convert Clock. The counter is started by
AI Sample Clock and continues to count down to zero, produces an
AI Convert Clock, reloads itself, and repeats the process until the sample is
finished. It then reloads itself in preparation for the next AI Sample Clock
pulse.
Using an External Source
Use one of the following external signals as the source of AI Convert
Clock:
•
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 Convert Clock (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.
AI Convert Clock Timebase Signal
The AI Convert Clock Timebase (ai/ConvertClockTimebase) signal is
divided down to provide on of the possible sources for AI Convert Clock.
Use one of the following signals as the source of AI Convert Clock
Timebase:
•
AI Sample Clock Timebase
•
20 MHz Timebase
AI Convert Clock Timebase is not available as an output on the I/O
connector.
