win_array_to

Parameters

data_array (POINTER(c_ushort))

The C array containing the data to be copied

memhandle (int)

This must be a memory handle that was returned by win_buf_alloc() when the buffer was allocated. The data will be copied into this buffer.

first_point (int)

Index of the first point in the memory buffer where data will be copied to.

count (int)

Number of data points to copy.

Notes

This function copies data from an array to a Windows global memory buffer. This would typically be used to initialize the buffer with data before doing an output scan. Using the first_point and count parameters it is possible to fill a portion of the buffer. This can be useful if you want to send new data to the buffer after a BACKGROUND + CONTINUOUS output scan has been started – for example, during circular buffering.

Although this function is available to Python, it is not necessary, since it is possible to manipulate the memory buffer directly by casting the memhandle returned from win_buf_alloc() to the appropriate type. This method avoids having to copy the data from an array to a memory buffer.

Refer to the following example:

From pyul import ul
count = 1000

# Allocate the buffer and cast it to an unsigned short
memhandle = ul.win_buf_alloc(count)
data_array = ctypes.cast(memhandle, ctypes.POINTER(ctypes.c_ushort))

# Calculate and store the waveform
for i in range(0, count):

data_array[i] = 2047 * (1.0 + math.sin(6.2832 * i / count))

# Output the waveform
ul.a_out_scan(0, 0, 0, count, 100, ULRange.BIP5VOLTS, memhandle, 0)

# Free the buffer and set the data_array to None
ul.win_buf_free(memhandle)
data_array = None

win_array_to_buf()

Prototype

Parameters

Notes