Assembly: Quanser.Hardware.Hil (in Quanser.Hardware.Hil.dll)
Syntax
Visual Basic (Declaration) |
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Public Sub WriteDigitalBuffer ( _ clock As Hil..::.Clock, _ frequency As Double, _ numSamples As Integer, _ channels As Integer(), _ buffer As SByte() _ ) |
C# |
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public void WriteDigitalBuffer( Hil..::.Clock clock, double frequency, int numSamples, int[] channels, sbyte[] buffer ) |
Visual C++ |
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public: void WriteDigitalBuffer( Hil..::.Clock clock, double frequency, int numSamples, array<int>^ channels, array<signed char>^ buffer ) |
JavaScript |
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function writeDigitalBuffer(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 to the list for board-specific details: .
- frequency
- Type: System..::.Double
The frequency in Hertz at which to write to the digital output channels. For example, if frequency is set to 1000, then the WriteDigitalBuffer method will write all the selected channels every millisecond.
- numSamples
- Type: System..::.Int32
The number of samples to generate. Each "sample" consists of all the digital output channels specified. For example, if frequency is set to 1000 and numSamples is set to 5000, then the WriteDigitalBuffer method will return after 5 seconds, having written 5000 samples. If 3 channels have been selected, then the buffer must therefore contain 15,000 elements.
- channels
- Type: array<
System..::.Int32
>[]()[]
An array containing the numbers of the digital output channels to which to write. Channel numbers are zero-based. Thus, channel 0 is the first channel, channel 1 the second channel, etc.
Select a board type to the list for board-specific details: .
- buffer
- Type: array<
System..::.SByte
>[]()[]
An array containing the binary values to write to the digital outputs. The array must contain channels.Length * numSamples elements. The array must be organized as a linear array of samples, with each sample consisting of a group of channels. For example, if digital output channels 0, 1 and 3 are being written, than the data must appear in the array as follows, where the numbers correspond to channel numbers:
0 1 3 0 1 3 ...
Remarks
The WriteDigitalBuffer method writes the specified number of samples to the digital channels at the given sampling frequency. This method does not return until all the data has been written.
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 WriteDigitalBuffer(Hil..::.Clock, Double, Int32, array<Int32>[]()[], array<SByte>[]()[]) method failing to write 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; double [] buffer = new double [samples * channels.Length]; int s, c; for (s = 0; s < samples; s++) { for (c = 0; c < channels.Length; c++) { buffer[s * channels.Length + c] = (s % (c + 2)) >= (c + 2)/2; } } card.WriteDigitalBuffer(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 Double Dim time As Double Dim s As Integer Dim c As Integer For s = 0 To samples time = s / frequency For c = 0 To channels.Length buffer(s * channels.Length + c) = (s Mod (c + 2)) >= (c + 2)/2 Next Next card.WriteDigitalBuffer(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<double>^ buffer = gcnew array<double>(samples * channels->Length); double time; int s, c; for (s = 0; s < samples; s++) { time = s / frequency; for (c = 0; c < channels->Length; c++) { buffer[s * channels->Length + c] = (s % (c + 2)) >= (c + 2)/2; } } card->WriteDigitalBuffer(Hil::Clock::Hardware0, frequency, samples, channels, buffer); |
Exceptions
Exception | Condition |
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Quanser.Hardware..::.HilException | If the write cannot be performed then an exception is thrown. This situtation typically arises if the board does not support digital outputs or the hardware resources required are in use by a task. |