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Measurement Computing Personal Daq rev.6.0 User Manual

Page 130

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A-12 API Custom Program Modules Appendix A,

878495

Personal Daq User’s Manual

If the handle is still –1 at this point, we know that either a Personal Daq/56 device was not located on the
system, or that whatever Personal Daq/56 device was located on the system could not be properly opened.

If handle& = -1 Then

Print "Cannot open PersonalDaq!"

Exit Sub
End If

An iteration on the channel count is used to initialize the scan sequence arrays and configure the frequency
and pulse counter channels. The following table indicates the content of the scan sequence arrays after this
iteration is completed:

Subscript

Gain Sequence Array

gains()

Channel
Sequence Array

channels()

Flag Sequence
Array

flags()

Analog Input Channels

0 PGainX1

1

(startChan)

AnaFlags

1 PGainX1

2

AnaFlags

2 PGainX1

3

AnaFlags

3 PGainX1

4

AnaFlags

4 PGainX1

5

AnaFlags

5 PGainX1

6

AnaFlags

6 PGainX1

7

AnaFlags

7 PGainX1

8

AnaFlags

8 PGainX1

9

AnaFlags

9 PGainX1

10

AnaFlags

Digital Ports

(

Does not apply to Personal Daq/54

)

10 PGainX1

1

(startChan)

DigFlags

11 PGainX1

2

DigFlags

Frequency Input / Pulse Count Channels

(

Does not apply to Personal Daq/54

)

12 PGainX1

1

(startChan)

FreqFlags

13 PGainX1

2

FreqFlags

14 PGainX1

3

CtrFlags

15 PGainX1

4

CtrFlags

For i = 0 To ChanCount
If (0 <= i) And (i < 10) Then
' Analog input channels
chans&(i) = startChan + 1
flags&(i) = AnaFlags
ElseIf (10 <= i) And (i < 12) Then
' Digital I/O ports
chans&(i) = startChan + (i - 10)
flags&(i) = DigFlags
ElseIf (12 <= i) And (i < 14) Then
' Frequency input channels configured for frequency input
chans&(i) = startChan + (i - 12)
flags&(i) = FreqFlags

The VBdaqSetOption function is used to set individual channel options. The sequence of calls below
configures the current channel chans&(i&) to measure 0 pulses per scan (DcotpDaqPulses) based on time
measurements between the successive rising edges of the input signal, disables debouncing, sets the
minimum and maximum values for the frequency range (maximum frequency range value is 1000 Hz), and
configures the measurement rate to be 1 Hz.

This manual is related to the following products: