Measurement-computing WaveBook rev.3.0 Manual de usuario descargar pdf (Pagina 192)

C-18 daqX API - Programming Models,

6-22-99

WaveBook User’s Manual

Set the scan configuration for channels 1 to 8 with a gain of ×1 in unipolar analog mode:

ret& = VBdaqAdcSetMux&(handle&, 1, channels&, DgainX1&,

DafUniPolar&+DafAnalog&)

Set the post-trigger scan frequency:

ret& = VBdaqAdcSetFreq&(handle&, freq!)

Set the trigger source to a software trigger command; the rest of the parameters have no effect on a software

trigger:

ret& = VBdaqAdcSetTrig&(handle&, DatsSoftware&, DatdRisingEdge&, 0,

HYSTERESIS%, 1)

Set the direct-to-disk filename with no pre-write, in append mode; also available is:

ret& = VBdaqAdcSetDiskFile&(handle&, "adcex8.bin", DaomAppendFile&, 0)

Start reading data in the background mode with cycle mode on and updateBlock:

ret& = VBdaqAdcTransferSetBuffer&(handle&, buf%(), BLOCK&, DatmCycleOn& +

DatmUpdateBlock&)

ret& = VBdaqAdcTransferStart&(handle&)

ret& = VBdaqAdcArm&(handle&)

ret& = VBdaqAdcSoftTrig&(handle&)

Monitor the progress of the transfer:

active& = -1

While active& <> 0

ret& = VBdaqAdcTransferGetStat&(handle&, active&, retCount&)

Wend

Print "Acquisition complete:"; retCount&; "scans acquired."

Close the device:

ret& = VBdaqClose&(handle&)

Now we convert the binary file to a text file. There is no simple way to do this, so it is necessary to open

the file and manipulate it by hand.

First, open the binary file:

Open "adcex8.bin" For Input As 1

Next, get a handle for the file; this is one of the windows API calls, CreateFile (it doesn’t actually

create anything, however).

fileHandle& = CreateFile(binFile, GENERIC_READ, &H1, "", CREATE_ALWAYS,

FILE_ATTRIBUTE_NORMAL, "")

Now open the text output file where the converted data will be written:

Open "adcex8.txt" For Output As 2

Next, actually convert the binary data to text:

Convert BLOCK unpacked scans to packed bytes:

scanCount& = BLOCK&

sampleCount& = scanCount& * channels&

wordCount& = sampleCount& * 3 / 4

byteCount& = 2 * wordCount&

Read the packed bytes from the input file, and get the number of bytes actually read. The UBound()and

Lbound()functions just return the upper and lower bounds of the buffer. Get #1 retrieves data from the

file and stores it in the buf() array.

Dim sz&

sz& = UBound(buf%) - LBound(buf%)

For i& = 0 To sz&

Get #1, i&, buf(i&)

Next i&

byteCount& = sz

Next, convert the data just read into the buffer from packed bytes to unpacked scans:

wordCount& = byteCount& / 2

sampleCount& = wordCount& * 4 / 3

scanCount& = sampleCount& / channels&

Unpack the packed data using the same buffer. This command can be called even if the WaveBook if not

online or connected.

ret& = VBdaqCvtRawDataFormat&(buf%(), DacaUnpack, BLOCK&, channels&,

scanCount&)

1 2 ... 187 188 189 190 191 192 193 194 195 196 197 ... 235 236

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