Assembly: Quanser.Hardware.Hil (in Quanser.Hardware.Hil.dll)
Syntax
Visual Basic (Declaration) |
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Public Sub ReadDigitalWriteDigitalBuffer ( _ clock As Hil..::.Clock, _ frequency As Double, _ numSamples As Integer, _ inputChannels As Integer(), _ outputChannels As Integer(), _ inputBuffer As SByte(), _ outputBuffer As SByte() _ ) |
C# |
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public void ReadDigitalWriteDigitalBuffer( Hil..::.Clock clock, double frequency, int numSamples, int[] inputChannels, int[] outputChannels, sbyte[] inputBuffer, sbyte[] outputBuffer ) |
Visual C++ |
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public: void ReadDigitalWriteDigitalBuffer( Hil..::.Clock clock, double frequency, int numSamples, array<int>^ inputChannels, array<int>^ outputChannels, array<signed char>^ inputBuffer, array<signed char>^ outputBuffer ) |
JavaScript |
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function readDigitalWriteDigitalBuffer(clock, frequency, numSamples, inputChannels, outputChannels, inputBuffer, outputBuffer); |
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 read from the digital input channels and write to the digital output channels. For example, if frequency is set to 1000, then the ReadDigitalWriteDigitalBuffer method will read all the input channels and write all the output channels every millisecond.
- numSamples
- Type: System..::.Int32
The number of samples to generate. Each "sample" consists of all the digital input channels and all the digital output channels specified. For example, if frequency is set to 1000 and numSamples is set to 5000, then the ReadDigitalWriteDigitalBuffer method will return after 5 seconds, having read 5000 samples and written 5000 samples. If three input channels have been selected, then the inputBuffer will contain 15,000 elements. If two output channels have been selected, then the outputBuffer must contain 10,000 elements.
- inputChannels
- Type: array<
System..::.Int32
>[]()[]
An array containing the numbers of the digital input channels from which to read. 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: .
- outputChannels
- 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: .
- inputBuffer
- Type: array<
System..::.SByte
>[]()[]
An array for receiving the binary values read from the digital inputs. The array must contain inputChannels.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 ...
- outputBuffer
- Type: array<
System..::.SByte
>[]()[]
An array containing the binary values to write to the digital outputs. The array must contain outputChannels.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 ReadDigitalWriteDigitalBuffer method reads the specified number of samples from the digital input channels and writes to the specified digital output channels at the given sampling rate in a single method call. Each sampling instant, the write operation occurs immediately following the read operation. Since the read-write operation occurs at the lowest level the read and write occur virtually concurrently. The method does not return until all the data has been read and written. This method is particularly useful for system identification since the read and write operations are synchronized. In particular, the value read in one sampling instant is the result of the write operation in the previous sampling instant.
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 ReadDigitalWriteDigitalBuffer(Hil..::.Clock, Double, Int32, array<Int32>[]()[], array<Int32>[]()[], array<SByte>[]()[], array<SByte>[]()[]) method failing to read or write the digital I/O as expected. |
Examples
C# | Copy Code |
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int [] inputChannels = { 0, 1, 2, 3 }; int [] outputChannels = { 5, 6 }; double frequency = 1000; int samples = 5000; sbyte [] inputBuffer = new sbyte [samples * inputChannels.Length]; sbyte [] outputBuffer = new sbyte [samples * outputChannels.Length]; int s, c; for (s = 0; s < samples; s++) { time = s / frequency; for (c = 0; c < outputChannels.Length; c++) { outputBuffer[s * outputChannels.Length + c] = (s % (c + 2)) >= (c + 2)/2; } } card.ReadDigitalWriteDigitalBuffer(Hil.Clock.Hardware0, frequency, samples, inputChannels, outputChannels, inputBuffer, outputBuffer); |
Visual Basic | Copy Code |
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Dim inputChannels() As Integer = {0, 1, 2, 3} Dim outputChannels() As Integer = {5, 6} Dim frequency As Double = 1000 Dim samples As Integer = 5000 Dim inputBuffer(samples * inputChannels.Length - 1) As SByte Dim outputBuffer(samples * outputChannels.Length - 1) As SByte Dim s As Integer Dim c As Integer For s = 0 To samples time = s / frequency For c = 0 To outputChannels.Length outputBuffer(s * outputChannels.Length + c) = (s Mod (c + 2)) >= (c + 2)/2 Next Next card.ReadDigitalWriteDigitalBuffer(Hil.Clock.Hardware0, frequency, samples, _ inputChannels, outputChannels, _ inputBuffer, outputBuffer) |
Visual C++ | Copy Code |
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array<int>^ inputChannels = { 0, 1, 2, 3 }; array<int>^ outputChannels = { 0, 1 }; double frequency = 1000; int samples = 5000; array<char>^ inputBuffer = gcnew array<char>(samples * inputChannels->Length); array<char>^ outputBuffer = gcnew array<char>(samples * outputChannels->Length); double time; int s, c; for (s = 0; s < samples; s++) { time = s / frequency; for (c = 0; c < outputChannels->Length; c++) { outputBuffer[s * outputChannels->Length + c] = (s % (c + 2)) >= (c + 2)/2; } } card->ReadDigitalWriteDigitalBuffer(Hil::Clock::Hardware0, frequency, samples, inputChannels, outputChannels, inputBuffer, outputBuffer); |
Exceptions
Exception | Condition |
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Quanser.Hardware..::.HilException | If the read or write cannot be performed then an exception is thrown. This situtation typically arises if the board does not support digital inputs or outputs or the hardware resources required are in use by a task. |