17-2000 C
2020-09-17
44(50)
ADQ8-8C Manual
17-2000 C 2020-09-17
44(50)
7.6.1
Transfer buffers
The data transfer buffers are the kernel buffers in
. These buffers are used by the DMA and
the ADQAPI to transfer the data from the ADQ digitizer to the host PC.
The transfer buffers are owned and managed by the ADQAPI, but the user sets the size and number of
buffers with the command
SetTransferBuffers
.
7.6.2
User’s buffers
The user’s buffers in
are allocated and managed by the user. The ADQAPI recreates the
data record and puts the result in these buffers.
Create the buffers using
malloc
. Then provide the pointers of these buffers to the ADQAPI through the
command or
GetDataWHTS
.
The user’s buffers consist of two sets of buffers; one for header information and one for data. The
header is always 40 bytes per record and the content is described in
. The data buffer size
is depending on the amount of data in each record. For FWDAQ, the record size is always constant and
the buffer size can be set to match the record size. The example code in ADQAPI_example
1
illustrate
how to handle data buffers in general.
7.7 Streaming transfer mode
Streaming transfer mode is described in
7.8 Users application software consuming data
The users application can consume the data in different ways. Some examples are in
. The
component “disk” is used for illustrating the end point for the data. It may also be a display or some
other device such as an alarm.
Figure 34: Timing of user-scheduled data transfer.
1. The ADQAPI_example is found in the folder installation of the digitizer software.
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