Triggering System - Tektronix 2212 Service Manual

Triggering System
2212 Service Manual
Product Description
The storage system has two acquisition modes, selected by the SEC/DIV
switch setting:
- RECORD mode. The SEC/DIV must be set to 0.2 SEC/DIV or faster. A
full record is acquired before the acquired data is displayed on the crt
screen. All triggering modes are selectable.
- ROLL
mode. The SEC/DIV must be set to 0.1 SEC/DIV or slower. Every
new acquired data point is displayed immediately to the right side of
the crt screen and the complete display is shifted one position to the
left. Triggering is disabled, except in SGL SWEEP (single sweep) mode.
"ROLL" is displayed in the crt readout.
With the 2212 inX-Y Store mode, the SEC/DIV and /or the EXT CLOCK
INPUT determine the sample rate. The External Clock Input (EXT CLK )pro-
vides input for external clock signals to the storage circuit when the SEC/DIV
switch is in one of the two EXT CLK positions (RECORD or ROLL).
The triggering system provides triggering from the channel
1
and/or channel 2
signals or from the external trigger input
(EXT INPUT OR Z). Types of trigger signals recognized include:
Internal : This type of triggering is fully configurable for
LEVEL, SOURCE, MODE, COUPLING, and SLOPE.
External : This triggering source is configurable for SLOPE,
LEVEL, MODE, and COUPLING like the internal sources.
You can choose the pre-trigger point within the acquired waveform record
by selecting the amount of pre-trigger (25% or 75%)with the PRETRIG
switch.
The hold-off time can be adjusted with the trigger HOLD OFF control.
The EXT OR Z input, at the bottom of the TRIGGER section, can be used to
apply either an external trigger signal to the trigger circuit or an external
Z-axis (display intensity) control signal to the Z-axis circuit.
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