GW Instek GOS-6200 - Manual (Page 15)

GOS-6200 OSCILLOSCOPE
USER MANUAL
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(27)TRIGGER LEVEL/TV LINE SELECT—Control knobs
TRIGGER LEVEL
Turning the control knob causes a different trigger input setting
(voltage), and set to a suitable position for the starting of triggered
sweep of the waveform. An approximate trigger level setting (voltage)
value will be displayed in the readout. When rotate clockwise the
control knob, the trigger point moves toward the positive peak of the
trigger signal and rotate it counterclockwise to move the trigger point
toward the negative peak of the trigger signal.
When the setting (voltage) value is out of the changing portion of the
observation waveform, the synchronization sweep stops. Sometimes a
“?” will be displayed on the left of the valued display, that indicates
that direct reading is impossible if AC, HFR, LFR, NR coupling or
VAR of vertical deflection is set.
TV LINE SELECT
If in the TV LINE trigger mode, the knob can only control the TV line
numbers.
(28)COUPLING/FLD 1/2 –Pushbutton and indicator LEDs.
Pressing the pushbutton to select the trigger coupling. The actual
setting is indicated by a LED and by the readout (“source, slope, AC”).
Each time when the COUPLING pushbutton is pressed the trigger
coupling changes in the sequence:
AC—DC—HFR—LFR—NR—AC
AC
Attenuates trigger signal frequency components below 10Hz and
blocks the DC component of the signal.
AC coupling is useful for triggering on AC waveforms that have a
large DC offset.
GOS-6200 OSCILLOSCOPE
USER MANUAL
⎯ 25 ⎯
DC
Couple DC and all frequency components of a triggering signal to the
trigger circuitry.
DC coupling is useful for most signals, especially for providing a
stable display of low-frequency or low-repetition-rate signals.
HFR (High Frequency Reject)
Attenuates high-frequency triggering signal components above 40kHz.
HFR coupling is useful for providing a stable display of low-frequency
components of complex waveforms and eliminates high-frequency
interference from the trigger signal.
LFR (Low Frequency Reject)
Attenuates low-frequency triggering signal components below 40kHz
and blocks the DC component of the trigger signal.
LFR coupling is useful for producing stable triggering on the high-
frequency components of complex waveforms and rejecting low-
frequency interference or power supply hum from the trigger signal.
NR (Noise Reject)
Decrease the maximum trigger bandwidth for high frequency signals,
as in DC coupling condition, lower frequency signal parts are not
affected.
FLD 1/2
If set to TV LINE trigger mode, select the video field 1 or 2 (even or
odd) by pressing the pushbutton. When the pushbutton of FLD 1/2 is
pressed, the field 1 or 2 will be changed in the sequence as follows:
FLD 1—FLD 2—FLD 1