10-5
IM WT1801-01EN
Trigger (Trigger Settings)
The trigger determines when a waveform is displayed. A trigger is said to “occur” when the trigger condition is
met and a waveform is displayed.
Trigger Mode (Mode)
The trigger mode determines the conditions for updating the display. Select from the following options.
• Auto (Auto mode)
If the trigger conditions are met before an approximately 100 ms timeout, the WT1800 updates the displayed
waveforms on each trigger occurrence. If not, the WT1800 automatically updates the displayed waveforms. If
the period of the trigger signal is greater than 100 ms, the display is updated as the two conditions described
above alternate. If this occurs, use Normal mode.
• Normal (Normal mode)
The WT1800 only updates the waveform display when the trigger conditions are met. If no triggers occur, the
display is not updated. If you want to view waveforms that the WT1800 cannot trigger on, or if you want to
check the ground level, use Auto mode.
• OFF
The trigger feature does not function. The display is updated at the data update interval. There are limitations
on the waveform display feature.
Trigger Source (Source)
The signal that the WT1800 checks for the trigger condition is referred to as the trigger source. Select from the
following options. The available options vary depending on the installed elements.
U1, I1, U2, I2, U3, I3, U4, I4, U5, I5, U6, I6, and Ext Clk (external clock)
*
* When you select Ext Clk, the external signal applied to the external clock input connector (EXT CLK) on the
rear panel is used as the trigger source. For the EXT CLK connector specifications, see section 4.3 in the
getting started guide, IM WT1801-03EN. When Ext Clk is set as the trigger source, the trigger level setting is
invalid.
Trigger Slope (Slope)
Slope refers to the signal movement from a low level to a high level (rising slope) or from a high level to a low
level (falling slope). When the slope is used as one of the trigger conditions, it is called a trigger slope.
The following trigger slope settings are available for triggering the WT1800.
•
:
An edge is detected when the trigger source changes from a level below the trigger level to a level
above the trigger level (rising).
•
:
An edge is detected when the trigger source changes from a level above the trigger level to a level
below the trigger level (falling).
•
: The WT1800 triggers on both rising and falling edges.
Trigger Level (Level)
The trigger level is the level at which the trigger slope is determined. When the trigger source passes through
the trigger level on a rising or falling edge, a trigger occurs.
• You can select a value between 0.0 and ±100.0%.
• A value of 100% corresponds to half the height of the waveform display. If the zero level of the input signal
is set to the center of the vertical axis, 100% corresponds to the top of the waveform display, and –100%
corresponds to the bottom of the waveform display. The upper and lower limits of the waveform display
correspond to three times the voltage or current measurement range of each element when the crest factor is
set to CF3 and six times when the crest factor is set to CF6. When scaling is used, the upper and lower limits
correspond to three or six times the scaled ranges.
• When Ext Clk is set as the trigger source, the trigger level setting is invalid.
10 Waveform Display