Konica Minolta PCI-1712L user manual 3 About-Trigger Acquisition Mode

Chapter 5

wSet to About-Trigger Acquisition Mode

wThe sample clock source and sample rate

wThe trigger source and edge type

wThe total acquired sample number N

wThe specific sample number M before the trigger event. The range of preset sample number is 2 samples minimum and is limited on basis of memory size of your host PC.

In about-trigger mode, users must first designate the size of the allocated memory and the amount of samples to be snatched after the trigger event happens. The about-trigger acquisition starts when the first clock signal comes in. Once a trigger event happens, the on-going data acquisition will continue until the designated amount of samples have been reached. When the PCI-1712/1712L detects the selected about-trigger event, the card keeps acquiring the preset number of samples, and kept the total number of samples on the FIFO.

Trigger Event

Acquired number of

samples M after trigger

event happened

1	2	3	N-M	N
				t

Total Acquired sample number: N

Figure 5-3: About-Trigger Acquisition Mode

qPre-Trigger Acquisition Mode

Pre-Trigger mode is a particular application of about-trigger mode. Use pre-trigger acquisition mode when you want to acquire data before a specific trigger event occurs. Pre-trigger acquisition starts when you start the operation and stops when the trigger event happens. Then the specific number of samples will be reversed in the FIFO before the pre-trigger event occurred. Please specify the following parameters, when using software in Pre-trigger acquisition mode:

wSet to Pre-Trigger Acquisition Mode

wThe sample clock source and sample rate

wThe trigger source and gate type

wAssume the total acquired sample number is N, then set the total sample number to be N+2.

PCI-1712/1712L User’s Manual	– 36 –	Advantech Co., Ltd.
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