Scientific SMO1000A-S, Руководство пользователя

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User Manual SMO1000A-S
83/176
Pattern Trigger
The Pattern trigger identifies a trigger condition by looking for a specified pattern. The
pattern trigger can be expanded to incorporate delays similar to other triggers. Pattern
durations are evaluated using a timer. The timer starts on the last edge that makes the
pattern
―
true
ǁ
. Potential triggers occur on the first edge that makes the pattern false,
provided that the time qualifier criterion has been met.
The oscilloscope
provides 4 patterns: logical AND, OR, NAND and NOR combination of the channels.
Each channel can set to low, high or invalid.
Do the following steps to set pattern trigger:
1. Press the
Setup
button on the front panel to enter the TRIGGER function menu.
2. Press the Type softkey; turn the Universal Knob to select Pattern, and then push
down the knob to confirm.
3. Press each channel softkey to select Invalid , High or Low .
Low sets the pattern to low on the selected channel. A low is a voltage level that
is less than the channel's trigger level or threshold level.
High sets the pattern to high on the selected channel. A high is a voltage level
that is greater than the channel's trigger level or threshold level.
Invalid sets the pattern to don't care on the selected channel. Any channel set to
don't care is ignored and is not used as part of the pattern.
However, if all channels in the pattern are set to
Invalid
, the oscilloscope will not
trigger.
Adjust the trigger level for the selected analog channel by turning the Trigger
Level knob. Invalid doesn’t need to set trigger level.
4. Press the Next Page softkey to enter the second page of the pattern trigger menu.
5. Press the Logic softkey and then turn the Universal Knob to select the desired logic
combination AND , OR , NAND or NOR .
6. Press the Limit Range softkey; then turn the Universal Knob to select the desired
option.
< (Less Than) – when the pattern is present for less than a time value.