User manual

32
UNI-T
®
UT4000 User Manual
Adjusting the Holdoff Time
You can adjust the holdoff time to observe complicated waveforms (e.g. pulse string
series). Holdoff time means the data acquisition cycle of the digital storage oscilloscope.
It is an exact multiple of the cycle of the complicated waveform being tested, thus
synchronization is possible. For example, you can display one group of pulse series stably
by adjusting holdoff time, as shown in Figure 2-17.
For the holdoff menu please see the table below :
Table 2-13
Function Menu Setup Explanatory Note
Window
⎯
Press [F1] to switch between “main window”
and “window extension”.
⎯
Dual time base Time base mode
Channel
Time base graticule
M2 shift
Main time base or dual time base.
For the selection of displaying CH1 or CH2.
Selecting main time base M1 or delay time
base M2.
Selecting fine tune or coarse tune shift.
⎯
Holdoff Adjust holdoff time with the multifunction
control knob.
Figure 2-17 Use the holdoff function to synchronize complicated waveforms
Operation
1. Follow the normal signal synchronization procedure and select the edge and trigger
source in the trigger [MENU]. Adjust the trigger level to make the waveform display
as stable as possible.
2. Press the horizontal [MENU] key to display the horizontal menu.
3. Adjust the multifunction control knob in the upper front panel. The holdoff time will
change accordingly until the waveform display is stable.
Operation tips : Holdoff time is usually shorter than the “big cycle” time. When
observing the RS232 communication signal, it is easier to observe if the holdoff time is
slightly shorter than the starting edge time of every datum.
Trigger position