CompuScope SDK Manua.. - Egmont Instruments

Like in Single Record mode, there is a minimum post-trigger depth of each Multiple Record that can be
specified for a given CompuScope model. The depth can then be increased from this minimum in specific
increments. See your CompuScope hardware manual for minimum depth and depth increment values in
Multiple Record Mode.
The total number of Multiple Records that can be acquired is slightly less than the total acquisition memory
available divided by the post trigger depth. For instance, for a CompuScope with 1 MegaSamples of onboard
memory capturing 2048 point Multiple Records in single channel mode, almost 1 MegaSample /
2048 = 512 Multiple Records can be acquired (Note. 1 MegaSample = 1024 ×1024 Samples). The
CompuScope cannot capture exactly 512 records, since a few points of inter-Record padding is required
between sequential records. So, slightly more than 2048 points are acquired for each record and ,
consequently, less than 512 records can be acquired. The amount of padding is small (less than 10 points
for most CompuScope models), but slightly reduces the number of records that can be captured
As with Normal Single Record Acquisition, the GET DATA signal is strobed low to initiate a Multiple
Record acquisition. This clears the TRIGGER and RAM FULL signals and their status bits and initializes
the data acquisition counters to zero. The BUSY signal and status bit are now set to high. The data
conversion process does not begin until a trigger event occurs.
When a trigger event does occur, the sample depth counter begins to decrement. When this counter
expires, it clears both the TRIGGER signal and its status bit, (instead of the BUSY signal as in Single
record Mode). This allows another trigger event to again start the data capture process and acquired
another record. A minimal number of sample clocks is required to reset the TRIGGER signal before
another trigger event will be recognized. This number varies with CompuScope model number but is
under 20 for all current models.
The Multiple Record process continues until all of the requested records have been acquired. This event
clears the BUSY signal, thus ending the Multiple Record acquisition. The following figure is a detailed
timing diagram for a Multiple Record acquisition.
CompuScope API Reference Manual
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