Chapter 2
NI 5450 Overview
NI PXIe-5450 User Manual
2-44
ni.com
PXI_Trig<0..6>
—Sample clock (when K
≥
2), the Sample clock timebase
(when M
≥
2), and the Reference clock can be exported to the PXI_Trig
lines. The PXI standards allow for devices to route signals to other devices
in your PXI Express chassis to enhance device-to-device synchronization.
Refer to the chassis documentation for specifications to ensure the
reference signal is within tolerance. You must configure the device to
export the desired clock to the PXI_Trig line.
Refer to niFgen Export Signal VI or the
niFgen_ExportSignal
function
for more information about configuring the destinations for the desired
clock signal.
Onboard Memory
The NI 5450 signal generator uses an onboard memory that is 16-bits wide.
The minimum standard memory size for the NI 5450 is 128 MB. With the
minimum standard memory size, you can store very long waveforms on the
device and obtain reliable waveform generation at full sample rate of
400 MS/s. The NI 5450 also comes with higher memory options of 512 MB
or 2 GB.
The onboard memory is a single large memory area per channel that stores
both waveforms and sequence instructions to generate the waveforms. The
instructions for a complicated sequence can occupy a significant portion of
memory. The architecture of the NI 5450 allows you to load multiple
waveforms and multiple sequence instructions into the memory. The
following diagram illustrates NI 5450 memory allocation. A number of
waveforms are stored in the onboard memory ranging from 1 to
n
; there are
also a number of sequence instructions ranging in number from 1 to
m
. The
values of
n
and
m
depend on the waveform and instructions configured and
are ultimately limited by the amount of memory.
W
a
veform
2
W
a
veform
1
S
e
qu
ence
In
s
tr
u
ction
s
m
Free
Memory
S
e
qu
ence
In
s
tr
u
ction
s
1
S
e
qu
ence
In
s
tr
u
ction
s
2
W
a
veform
n
• • •
• • •
