National Instruments NI 6238 - Manual (Page 45)

Chapter 4 Analog Input
© National Instruments Corporation 4-19 NI 6238/6239 User Manual
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:
• Input PFI <0..5>
• RTSI <0..7>
• PXI_STAR
Note Refer to the NI 6238/6239 Specifications for the minimum allowable pulse width
and the propagation delay of PFI <0..5>.
Routing AI Convert Clock Signal to an Output
Terminal
You can route ai/ConvertClock (as an active low signal) out to any output
PFI <6..9> or RTSI <0..7> terminal.
PFI <0..5> terminals are fixed inputs. PFI <6..9> terminals are fixed
outputs.
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.
Figure 4-12 shows the relationship of ai/SampleClock to ai/ConvertClock.