Musical Instrument User Manual

5 - 24 FUNCTION REFERENCE
DELAY
Description:
Delay is the term that is used to define the time difference between the trigger
point of an acquisition and the starting point of the resulting trace. In an analog
oscilloscope, the trigger point is at the beginning of a trace, and the delay is said
to be zero. The use of a Delayed Timebase introduces a delay between the trigger
point of the Main Timebase and the start of the trace which is displayed with the
Delayed Timebase.
Three types of Delay.
This family of oscilloscopes has three types of adjustable delay :
1. Delay controlled by the DELAY control on the front panel. This is the amount of
time delay between the start of the Main Timebase and the Delayed Timebase.
This delay applies to the Analog mode, as well as to the Digital mode.
2. A delay between the trigger point and a signal acquisition. This delay is used
to ‘position’ the acquired input signal with respect to the trigger point. This type
of delay can be ‘positive’, as well as ‘negative’. The result is the acquisition of
posttrigger or pretrigger waveform data, respectively.
This delay is available in the digital mode only and is controlled with the
TRIGGER POSITION control.
3. Delay caused by counting EVENTS. Available in the digital mode only. The
use of EVENTS delay causes the acquisition to start after a user selectable
number of events has been counted.
Delay
A full description is given under Delayed Timebase.
Trigger position
Pretrigger
is used to observe a portion of the signal that occurs before the trigger
point. This trigger point is then indicated in the screen by a marker (s). The
maximum pretrigger is the acquisition length. In this case, the trigger point marker
is positioned on the right side of the screen and the entire record contains
pretrigger information. The pretrigger view is indicated (in divisions) in the bottom
of the screen.
Posttrigger
is used for time delay and is expressed in seconds or fractions
thereof. The maximum delay depends on the setting of the main timebase.
Maximum trigger delay is 100 divisions; the resolution is 1/50 of the timebase
TIME/DIV setting.
Event delay
Event delay postpones triggering until a specific number of trigger events have
occurred. The trigger event is defined in the EVENT DELAY sub menu of the TB
MODE. Its definition consists of a signal source and a trigger level (event level).