Tektronix 2245A Operator's Manual page 41

RUNS AFTER—Starts the B sweep immediately after the delay time
selected by the |<- OR DELAY control.
The Trigger MODE must be in RUNS AFTER before time measure­
ments can be selected when the Horizontal MODE is ALT or B. A time
measurement will be canceled if the Trigger MODE is changed from
RUNS AFTER while in the ALT or B Horizontal MODE.
NORM —The B sweep is triggered when an adequate trigger signal is
received after the delay time condition has been met. When there is
no trigger signal, there is no B sweep trace.
TV LINE FROM A SOURCE—Starts the B sweep at the beginning of
the video signal line received after the delay time has been met.
SLOPE polarity defaults to the A Trigger SLOPE. This must match the
composite sync polarity to obtain correct triggering on the horizontal
sync pulse.
37
( ) SOURCE
ca to rs—Select the trigger source for either the A or the B Trigger
system as directed by the A/B SELECT button. Pressing the
Up-/Down-Arrow SOURCE buttons selects the trigger source (for A
or B trigger system) as shown by SOURCE lights.
VERT—Selects the trigger signal from the displayed waveforms.
The TRIGGER MODE and VERTICAL MODE switch settings determine
the trigger signal source selection. When VERT is selected, one or
more of the SOURCE lights will be on to indicate the trigger signal
source. See Table 2-1 for VERT Trigger SOURCE selections.
CH 1—The signal applied to the CH 1 OR X input connector Is the
source of the trigger signal.
CH 2—The signal applied to the CH 2 input connector is the source of
the trigger signal.
CH 3—The signal applied to the CH 3 input connector is the source of
the trigger signal.
2245A Operators
Controls, Connectors, and Indicators
(U p -A rro w and D ow n-A rrow ) B uttons and Indi­
2-15