Advantech iDAQ-817, User Manual

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13 iDAQ-817_821 User Manual
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Figure 3.2 Buffered analog input acquisition.
The start and stop mechanism of the data acquisition are controlled by the start trig -
ger and stop trigger respectively. When configuration is completed, the acquisition
engine of the iDAQ chassis is at standby state. After receiving a start trigger, acquisi -
tion becomes active and each rising edge of the sample clock acquires one analog
input sample. The acquisition active period lasts until a stop trigger is received, which
ends the acquisition. This is shown in Figure 3.3.
Figure 3.3 Start and stop triggers of the analog input acquisition.
The start and stop of data acquisition can also be delayed in the number of samples
after receiving the corresponding trigger signal. As shown in Figure 3.4, the start of
acquisition is delayed by 3 samples after receiving a start trigger, and the stop of
acquisition is delayed by 2 samples after receiving a stop trigger.