Introduction 6
CG635 Synthesized Clock Generator
Modify
Stepping Up and Down
The MODIFY section is used to step the currently displayed item up or down by a
programmed amount. Each of the six standard display items listed in the DISPLAY
section has a step size associated with it. Normally, pressing the MODIFY
Ÿ
and
ź
keys causes the displayed item to increment and decrement, respectively, by the
associated step size.
Step Size
The step size for the current standard display can be viewed by pressing the ‘STEP SIZE’
key. Pressing ‘STEP SIZE’ a second time toggles the view back to the standard display.
When the step size is being viewed, the STEP LED in the main display will be turn on.
To view the frequency step size, press ‘FREQ’, ‘STEP SIZE’, sequentially. Pressing
‘FREQ’ ensures that frequency is the current standard display. Pressing ‘STEP SIZE’
then toggles the main display to the step size associated with frequency.
The step size can be changed in a number of ways. If the current step size is being
displayed, the user can modify the current step size in one of two ways. First, you can
enter a new value with the numeric keys in the ENTRY section and complete the entry by
pressing an appropriate units key. Second, you can increment and decrement the current
step size by exact factors of ten by pressing the MODIFY
Ÿ
and
ź
keys, respectively.
For example, if the currently displayed frequency step size is 1.000 Hz, then the step size
can be increased to 10.000 Hz by pressing MODIFY
Ÿ
once.
The step size can also be changed, even when the current step size is not being displayed.
This is accomplished by accessing the SHIFTED functions
ĸ
and
ĺ
shown above the
MODIFY
Ÿ
and
ź
keys, respectively. For example, pressing ‘SHIFT’, MODIFY
Ÿ
,
sequentially will increase the associated step size to the next exact factor of ten.
When the step size of a standard display item is an exact factor of ten, the corresponding
digit in the main display will blink. This provides a convenient visual cue to let the user
know which digit will change when the user presses the MODIFY
Ÿ
and
ź
keys. 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.
Remote and Local Mode
The REM LED turns on when the CG635 is placed in remote mode by the GPIB bus. In
this mode, all the front panel keys are disabled and the instrument can only be controlled
via the GPIB bus. The user can return to normal, local mode by pressing the ‘STEP
SIZE’ key once. The ‘LOCAL’ label above the key indicates the dual functionality of the
‘STEP SIZE’ key.
