National Instruments PXI-6289 User Manual page 227

Appendix B Timing Diagrams
_i
Selected Reference Trigger
Terminal
_i
Terminal
Terminal
_i
_i
Terminal
_i
_i
_i
Terminal
_i
The following signals are used in Figure B-1 and in the following sections:
Terminal—Refers to any device terminal, such as PFI or RTSI. These terminals are used
•
as inputs and as outputs for signals.
_i—Refers to any internal signal available to the analog input timing engine for use. In the
•
case of signals coming from an external terminal, this is the signal after is been through the
first input buffer. _i also can refer to other internal signals such as internal timebases or
signals coming from other blocks.
POUT—Refers to any output signal right before it is driven to an output terminal.
•
Convert Clock Timebase and Sync Convert Clock Timebase—Convert Clock Timebase
•
is the source signal used to generate the signal that will actually cause the ADC to do a
conversion (p_AI_Convert). This signal can be an internal or external timebase that is
divided by the SI2 counter, or can be an external Convert Clock signal. Sync Convert Clock
Timebase is a signal related to Convert Clock Timebase that is used to synchronize external
signals before they are used by circuits running from Convert Clock Timebase.
Sample Clock Timebase and Sync Sample Clock Timebase—Sample Clock Timebase
•
is the source for the SI counter and can be used to generate the sample timing. Each Sample
Clock in turn triggers the generation of one or more converts. This signal can be an internal
or external timebase. Sync Sample Clock Timebase is a signal related to Sample Clock
Timebase that is used to synchronize external signals before they are used by circuits
running from Sample Clock Timebase.
B-2 | ni.com
Figure B-1. M Series Analog Input Timing Engine
Selected Start Trigger
Selected Pause Trigger
Sample Clock Timebase
Sync Sample Clock Timebase
Convert Clock Timebase
Sync Convert Clock Timebase
Selected Sample Clock
Reference Trigger
Start Trigger
Pause Trigger SI Start
SI
Counter
Block
SI_TC
SI2
Counter
Block
Start
POUT
POUT
POUT
(and Other Counters,
and Such of Timer Core)
POUT
POUT
SI2_TC
1
POUT
Terminal
Terminal
RTSI
Terminal
p_AI_Convert
Terminal