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Principles of Operation
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An external digital trigger event occurs when the DT300 Series board detects either a rising
(positive) or falling (negative) edge on the External TTL Trigger input signal connected to
screw terminal TB46 on the STP300 screw terminal panel (pin 56 of connector J1). The trigger
signal is TTL-compatible. Using software, specify the trigger source as a positive external
digital trigger or negative external digital trigger.
Trigger Acquisition Modes
DT300 Series boards can acquire data in post-trigger mode, pre-trigger mode, or about-trigger
mode. These trigger acquisition modes are described in more detail in the following
subsections.
Post-Trigger Acquisition
Use post-trigger acquisition mode (continuous mode) when you want to acquire data when a
post-trigger or retrigger, if using triggered scan mode, occurs.
Using software, specify:
• The dataflow as Continuous
• The trigger source to start the post-trigger acquisition (the post-trigger source) as any of
the supported trigger sources
Refer to
for more information on the supported conversion modes; refer to
for
information on the supported trigger sources.
Post-trigger acquisition starts when the board detects the post-trigger event and stops when
the specified number of post-trigger samples has been acquired or when you stop the
operation.
If you are using triggered scan mode, the board continues to acquire post-trigger data using
the specified retrigger source to clock the operation. Refer to
for more information on
triggered scan mode.
illustrates continuous post-trigger mode using a channel list with three entries:
channel 0, channel 1, and channel 2. Triggered scan mode is disabled. In this example,
post-trigger analog input data is acquired on each clock pulse of the A/D sample clock. When
it reaches the end of the channel list, the board wraps to the beginning of the channel list and
repeats this process. Data is acquired continuously (continuously-paced scan mode).
Figure 25: Continuous Post-Trigger Mode without Triggered Scan
Post-trigger event
Chan 0
Chan 1
Chan 2 Chan 0
Chan 1
Chan 2 Chan 0
Chan 1
Chan 2 Chan 0
Chan 1
Chan 2
A/D
Sample
Clock
Post-trigger data acquired
continuously
Содержание DT300 Series
Страница 1: ...DT300 Series UM 16501 T User s Manual Title Page ...
Страница 4: ......
Страница 10: ...Contents 10 ...
Страница 14: ...About this Manual 14 ...
Страница 15: ...15 1 Overview Features 16 Supported Software 18 Accessories 19 Getting Started Procedure 20 ...
Страница 21: ...Part 1 Getting Started ...
Страница 22: ......
Страница 58: ...Chapter 4 58 ...
Страница 69: ...Part 2 Using Your Board ...
Страница 70: ......
Страница 106: ...Chapter 6 106 ...
Страница 124: ...Chapter 8 124 ...
Страница 125: ...125 9 Troubleshooting General Checklist 126 Technical Support 128 If Your Board Needs Factory Service 129 ...
Страница 130: ...Chapter 9 130 ...
Страница 156: ...Appendix C 156 ...
Страница 164: ...Index 164 ...