Tektronix DPO3000 Series, Руководство пользователя

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Trigger Setup
For example, if the number of bytes is one, the oscilloscope will attempt to match the fi rst byte, second byte, third, and so
on within the packet.
If the number of bytes is two, the oscilloscope will try to match any two consecutive bytes, such as one and two, two and three,
three and four, and so on. If the oscilloscope
fi nds a match, it will trigger.
Speci fi c byte matching (non-rolling window matching for a speci fi c position in the packet) for I
2
C, SPI, and
CAN. You can trigger on a speci fi c byte for I
2
C, SPI and CAN in several ways:
For I
2
C and SPI, enter the number of bytes to match the number of bytes in the signal. Then use don’t cares (X) to mask the
bytes that you are not interested in.
For I
2
C, push the lower-bezel Trigger On to trigger on Address/Data . Push Address . On the side-bezel menu, push Address ,
and rotate multipurpose knobs a and b as needed. Set the address to don’t cares (X) if you want to mask the address. The
data will be matched starting at the fi rst byte without using a rolling window.
For CAN, triggering occurs when the user-selected data input matches the data and quali fi er in the signal starting at the fi rst
byte. Set the number of bytes to match the number of bytes of interest. Use the data quali fi er to perform: =, !=, <, >, >=,
and <= operations. Triggering on identi fi er and data always matches the identi fi er and data selected by the user, with the
data starting at the fi rst byte. No rolling window is used.
RS-232 Bus Trigger Data Matching
You can trigger on a speci fi c data value for RS-232 bytes. If you de fi ned an end-of-packet character to use for RS-232 bus
decoding, you can use the same end-of-packet character as a data value for trigger data matching. To do so, choose the Tx End of
Packet or the Rx End of Packet character as the Trigger On selection.
DPO3000 Series Oscilloscopes User Manual 129