Trigger Controls, Connector, And Indicator - Tektronix 2215A Instruction Manual

Operating Instructions— 2215A Service
Figure 2-6. Trigger controls, connector, and Indicator.
LEVEL control is restricted to the peak-to-peak
range of the trigger signal.
NORM— Sweep is initiated when an adequate trig­
ger signal is applied. In the absence of a trigger
signal, no baseline trace will be present.
TV FIELD— Press in both P-P AUTO and NORM
buttons. Permits triggering on television field sig­
nals. TRIGGER LEVEL control should be rotated
fully counterclockwise when triggering on TV sig­
nals with negative going sync and clockwise for
positive going sync.
(2 6 ) TRIG'D-READY Indicator— LED illuminates when ei­
ther P-P AUTO or NORM Trigger Mode is selected
and the A Sweep has been triggered (TRIG'D).
In single-sweep display, the LED illuminates to indi­
cate that the A Trigger circuit is armed (READY).
(2 7 ) A TRIGGER LEVEL Control— Selects the amplitude
point on the trigger signal at which the sweep is
triggered.
n j j ) SLOPE Switches— Selects the slope of the signal
that triggers the sweep.
OUT— When button is released out, sweep is trig­
gered from the positive-going slope of the trigger
signal.
2-6
IN— When button is pressed in, sweep is triggered
from the negative-going slope of the trigger signal.
(2 9 ) A SOURCE Switch— Determines the source of the
trigger signal that is coupled to the input of the A Trig­
ger circuit.
INT— Permits triggering on signals that are applied
to the CH 1 OR X and CH 2 OR Y input connec­
tors. The source of the internal signal is selected by
the A & B INT switch.
LINE— The power-source waveform is the source
of the trigger signal. This trigger source is useful
when vertical input signals are time related (multi­
ple or submultiple) to the frequency of the power-
input source voltage.
EXT— Permits triggering on signals applied to the
EXT INPUT connector.
(3 0 ) A&B INT Switch— Selects the source of the internal
triggering signal when the A SOURCE switch is set to
INT.
CH 1— The signal applied to the CH 1 OR X input
connector is the source of the trigger signal.
VERT MODE— The internal trigger source is deter­
mined by the signals selected for display by the
VERTICAL MODE switches. See Table 2-1 for
VERT MODE trigger source.
Table 2-1
VERT MODE Trigger Source
VERT MODE
CH 1 CH 1 OR X input signal.
CH 2 CH 2 OR Y input signal.
BOTH and ADD Algebraic sum of CH 1 OR X and
CH 2 OR Y input signals.
BOTH and CHOP Algebraic sum of CH 1 OR and CH
2 OR Y input signals.
BOTH and ALT Alternates between Channel 1 and
Channel 2 on every other sweep
(i.e. CH 1 OR X input signal triggers
the sweep that displays Channel 1,
and CH 2 OR Y input signal triggers
the sweep that displays Channel 2).
CH 2— The signal applied to the CH 2 OR Y input
connector is the source of the trigger signal.
Trigger Source