© National Instruments
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B-9
Figure B-8.
Convert Clock and Any Internal Signal Timing Diagram
Start Trigger
The Start Trigger is the signal that starts an AI acquisition. This signal can come from an external
source (through an external terminal) or from an internal source. One possible internal source is
a software-generated pulse. A multiplexer selects from all the possible sources (all of them at _i
level) and outputs a signal called Selected Start Trigger. Selected Start Trigger then gets sent to
the two timing levels in the AI section (the Convert Clock Timebase and the Sample Clock
Timebase timing level) for synchronization to each clock. Once the Convert Clock Timebase
timing domain has received a valid Start Trigger, the AI timing engine is ready to begin
generating converts, as soon as it receives a Sample Clock (beginning of a sample). Once the
Sample Clock Timebase domain has received a valid Start Trigger, the AI timing engine is ready
to begin generating Sample Clocks.
t
9
Delay from _i to Convert Clock
Timebase
PFI
16.2
39.1
RTSI
16.0
38.8
STAR
15.5
36.1
t
10
Delay from Convert Clock Timebase to
p_AI_Convert
—
6.0
13.0
t
11
Delay from Convert Clock Timebase to
Convert Clock, when exported to an
external terminal (POUT)
PFI
4.6
10.8
RTSI
4.6
10.5
Table B-4.
Convert Clock and Any Internal Signal Timing
Time
Description
Line
Min (ns)
Max (ns)
t
12
_i to p_AI_Convert in
external convert mode
PFI
22.2
52.1
RTSI
22.1
51.8
STAR
21.5
49.1
Table B-3.
Convert Clock Timing (Continued)
Time
Description
Line
Min (ns)
Max (ns)
_i
p_AI_Convert
t
12
Summary of Contents for PCI-6281
Page 1: ...PCI 6281...
