Operating instructions

University of Saskatchewan
Electrical Engineering Laboratory Equipment Manual
This unit, along with other scopes and analyzers, should be reset to factory default
settings before using. Press the Save/Recall button and then the Default Setup button to reset.
This unit, along with other scopes and analyzers, has an Auto-Scale button. Auto-Scale
automatically configures the scope to display the signals at its inputs. Students that use this
function will not learn the basic controls and how to display signals. The auto scale function can
be misleading when displaying a signal. In order to learn the operation of equipment, avoid the
Auto-Scale button. These units also do automatic measurements. Manual cursor measurements
are more accurate then automatic measurements. Use the cursor measurements for accurate
measurements and as a learning tool. Measurements should be taken at the center of the trace
width.
Quick Help > Press and hold down the button which help information is required for.
> Hold the button down to read.
> Release the button to return to the previous scope state.
Trigger Mode
Normal Mode > Only Triggers when conditions are met ( transition or/and a logic level).
Auto Mode > Forces a trigger when conditions are not met.
Auto level > Works with Edge trigger (analog or external).
> First it tries a normal trigger.
> If no normal trigger is found, then it searches for a transition signal and
sets the trigger level at 50% of the magnitude.
> If there is no signal transition, then it does an auto trigger and forces a
trigger.
In Auto or Normal mode, a trigger will not be recognized until the pre-trigger buffer is full. At
slow sweep speeds (ms/div), the trigger may not be found. Use Normal mode and wait for the
trigger indicator to flash before causing the trigger condition in the circuit.
HF Reject is a 50 kHz input low pass filter to the trigger circuit. Noise Rej increases the
trigger hysteresis band, thus reducing noise triggering. This also reduces trigger sensitivity. The
signal may have to be increased.