Assembly: Quanser.Hardware.Hil (in Quanser.Hardware.Hil.dll)
Syntax
Visual Basic (Declaration) |
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Public Sub ReadDigitalBuffer ( _ clock As Hil..::.Clock, _ frequency As Double, _ numSamples As Integer, _ channels As Integer(), _ buffer As SByte() _ ) |
C# |
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public void ReadDigitalBuffer( Hil..::.Clock clock, double frequency, int numSamples, int[] channels, sbyte[] buffer ) |
Visual C++ |
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public: void ReadDigitalBuffer( Hil..::.Clock clock, double frequency, int numSamples, array<int>^ channels, array<signed char>^ buffer ) |
JavaScript |
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function readDigitalBuffer(clock, frequency, numSamples, channels, buffer); |
Parameters
- clock
- Type: Quanser.Hardware..::.Hil..::.Clock
The clock used to time the operation. Note that some clocks allow faster sampling rates than others. See the Hil..::.Clock enumeration for more information on clocks.
Select a board type from the list for board-specific details: .
- frequency
- Type: System..::.Double
The frequency in Hertz at which to sample the digital input channels. For example, if frequency is set to 1000, then the ReadDigitalBuffer method will read all the selected channels every millisecond.
- numSamples
- Type: System..::.Int32
The number of samples to collect. Each "sample" consists of all the digital input channels specified. For example, if frequency is set to 1000 and numSamples is set to 5000, then the ReadDigitalBuffer method will return after 5 seconds with 5000 samples. If 3 channels have been selected, then the output buffer will contain 15,000 elements.
- channels
- Type: array<
System..::.Int32
>[]()[]
An array containing the numbers of the digital input channels to be read. Channel numbers are zero-based. Thus, channel 0 is the first channel, channel 1 the second channel, etc.
Select a board type from the list for board-specific details: .
- buffer
- Type: array<
System..::.SByte
>[]()[]
An array for receiving the binary values read from the digital inputs. The array must contain channels.Length * numSamples elements. The array is organized as a linear array of samples, with each sample consisting of a group of channels. For example, if digital input channels 0, 1 and 3 are being read, than the data appears in the array as follows, where the numbers correspond to channel numbers:
0 1 3 0 1 3 ...
Remarks
The ReadDigitalBuffer method reads the specified number of samples from the digital channels at the given sampling frequency. This method does not return until all the data has been read.
Many cards allow the digital I/O lines to be programmed as inputs or outputs. The digital I/O lines are configured as inputs or outputs using the SetDigitalDirections(array<Int32>[]()[], array<Int32>[]()[]) method. All the channels which will be used as digital inputs or outputs must be configured accordingly using this function. Failure to configure the digital I/O may result in the ReadDigitalBuffer(Hil..::.Clock, Double, Int32, array<Int32>[]()[], array<SByte>[]()[]) method failing to read the digital I/O as expected. |
Examples
C# | Copy Code |
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int [] channels = { 0, 1, 2, 3 }; double frequency = 1000; int samples = 5000; sbyte [] buffer = new sbyte [samples * channels.Length]; card.ReadDigitalBuffer(Hil.Clock.Hardware0, frequency, samples, channels, buffer); |
Visual Basic | Copy Code |
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Dim channels() As Integer = {0, 1, 2, 3} Dim frequency As Double = 1000 Dim samples As Integer = 5000 Dim buffer(samples * channels.Length - 1) As SByte card.ReadDigitalBuffer(Hil.Clock.Hardware0, frequency, samples, channels, buffer) |
Visual C++ | Copy Code |
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array<int>^ channels = { 0, 1, 2, 3 }; double frequency = 1000; int samples = 5000; array<char>^ buffer = gcnew array<char>(samples * channels->Length); card->ReadDigitalBuffer(Hil::Clock::Hardware0, frequency, samples, channels, buffer); |
Exceptions
Exception | Condition |
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Quanser.Hardware..::.HilException | If the read cannot be performed then an exception is thrown. This situtation typically arises if the board does not support digital inputs or the hardware resources required are in use by a task. |