6 - 24 THE CPL PROTOCOL
sample 2 bytes (Most Significant Byte + Least Significant Byte), representing
the 16 bit sample value (bit 16 = -32768, bit 15 = 16384, ..., bit 1 = 1).
Range: -32k (down) to +32k (up)
checksum 1 byte checksum of all sample bytes
(add one by one; result modulus 256)
Example:
In this example, a waveform of 512 points is generated in the computer and sent to
the oscilloscope. The display of the waveform on the oscilloscope screen consists
of two sine waves (amplitude = ± 3 vertical divisions and period (2π) = 5 horizontal
divisions). The Y-scale will be set at 500 Volts per division, and the X-scale at
50.0 µs per division. The following values can be calculated from these settings:
- The number of waveform amplitude points = 3 divisions * 6400 points/div. = 19200
(used in the example program)
- The number of waveform time points = trace length (512) / 2
*
2π) = 40.744
(used in the example program)
After running the example program, perform the following:
Select the default setup by pressing the front panel keys STATUS and TEXT
OFF at the same time.
Select the digital mode by pressing the ANALOG key.
Select the recall menu by pressing the RECALL key.
Use the TRACK button and the software keys to turn the m4 register display
on and the acq display off.
Press the STATUS key.
Example: 1000000011000111 = value -32569
byte 1 byte 2
byte 1 = 128 (value -32768)
byte 2 = 128+64+4+2+1 = 199 (value +199)
<Y_resolution> =- = 78.13E-3V
500 V/div.
6400 dots/div.
<X_resolution> =- = 1E-6s
50 µ/div.
50 dots/div.