Operation 14
CG635 Synthesized Clock Generator
Each of these parameters has an independent step size associated with it. When one of the
six main displays is active, the associated step size for the parameter can be displayed by
pressing the ‘STEP SIZE’ button in the MODIFY section of the front panel. Pressing the
‘STEP SIZE’ key again toggles the display back to the original parameter. When the step
size for a parameter is displayed, the STEP LED in the main display will be highlighted.
For example, to display the frequency, press the ‘FREQ’ key. Now that frequency is
displayed you can display the frequency step size by pressing the ‘STEP SIZE’ key. The
STEP LED should be highlighted in the main display. Pressing ‘STEP SIZE’ once more
toggles the display back to frequency. The STEP LED should now be off.
Changing a Parameter
To change a parameter, enter a new value using the numeric keys in the ENTRY section
of the front panel, and complete the entry by pressing an appropriate units key. Generally
speaking, only displayed parameters can be changed. For example, to change the
frequency to 10 kHz, press the following keys sequentially: ‘FREQ’, ‘1’, ‘0’, ‘kHz’.
Pressing ‘FREQ’ selects it for display and editing. Pressing ‘1’ initiates the parameter
change. Pressing ‘kHz’ completes the numeric entry and sets the frequency to 10 kHz.
The same techniques can be used to change the step size of a parameter. The only
difference is that the parameter step size must be displayed first, before entering a
new value.
If the user enters extra digits beyond the allowed resolution of a parameter, the extra
digits will be ignored. For example, the phase has a resolution of 1 degree at 1 GHz.
Entering a step size of 2.5 degrees will result in the step size being truncated to 2 degrees.
Stepping a Parameter
The six main parameters can be stepped up and down by their associated step sizes by
respectively pressing the
Ÿ
and
ź
keys in the MODIFY section of the front panel. For
example, if frequency is currently being displayed as 10.000000000 MHz, and the
frequency step size is 1.000 Hz, then pressing MODIFY
Ÿ
will change the frequency to
10.000001000 MHz. Pressing MODIFY
ź
will bring the frequency back to 10 MHz.
Step Sizes of Exact Factors of Ten
If a parameter’s step size is an exact factor of ten, then the corresponding digit in the
main display of the parameter will blink. This provides a visual cue to inform the user of
the digit that will change when the parameter is stepped up or down. For example, if the
frequency step size is 1.000 Hz, and the displayed frequency is 123456.789 Hz, then the
‘6’ will be blinking. Pressing the MODIFY
Ÿ
key will step the frequency up 1 Hz to
123457.789 Hz.
When a parameter step size is being displayed, the user can increase or decrease the step
size to the nearest exact factor of ten by pressing the MODIFY
Ÿ
and
ź
keys,
respectively. For example, if the current frequency step size is being displayed as
1.000 Hz, then pressing MODIFY
Ÿ
will increase to the step size to 10.000 Hz.
