Tektronix MDO4054-3, Руководство пользователя

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Acquire the Signal
2. The Thresholds , Label , Bus Display , and
Event Table menu items operate similarly to
how they work on other serial bus menus.
3. Push RT if you wish to change the Response
Time (RT) maximum and minimum default
values.
Physical Layer Bus Activity
Oscilloscope waveform traces from analog channels 1 to 4, digital channels D15 to D0, Math waveforms, and the traces you
see when you choose to display a bus always show the physical layer bus activity. In the physical layer display, bits that were
transmitted earlier are to the left, and bits that were transmitted later are to the right.
I2C, and CAN buses transmit the MSB (most signi fi cant bit) fi rst
SPI buses do not specify a bit order
RS-232 and LIN buses transmit the LSB (least signi fi cant bit) fi rst
NOTE. The oscilloscope displays the decode traces and event tables for all buses with the MSB on the left and LSB
on the right.
For example, an RS-232 signal (after the start bit) might be high, high, high, low, high, low, low, and high. Since the RS-232
protocol uses high for zero and low for one, this value would be 0001 0110.
Since the decode displays the MSB fi rst, the oscilloscope reverses the order of the bits and displays 0110 1000. If the bus
display is set to hex, the value displays as 68. If the bus display is set to ASCII, the value displays as h.
72 MDO4000 Series Oscilloscopes User Manual