Ametek 7280 Instruction Manual page 93

representing zero. If curve storage is already running, or if there is data in the curve
buffer, then a curve will be displayed with the most recent value at the right-hand
side of the screen.
Figure 5-27 shows the layout of the Single Graph menu. The curve is displayed in the
central section of the display, with the keys on either side being used to adjust the
axes and to select the data to be shown, as follows:-
SCALE keys
The top and bottom left-hand
limits of the vertical axis with a 1% resolution, the set maximum and minimum
values being shown adjacent to them.
AUTO SCALE keys
The upper and lower middle pairs of left-hand
upper and lower limits of the vertical axis to match the range present in the visible
section of the displayed curve.
There is no facility for adjusting the x-axis scale, which always shows up to 243
points. Hence if a curve of more than this number of points is acquired it will not be
possible to show all of the points on the display at the same time.
Curve Selection keys
The keys on the top right-hand side of the display are used to select the curve to be
shown from those stored in the curve buffer. All curves that can be stored may be
selected for display, except for EVENT, the two curves recording the reference
frequency (FRQ0 and FRQ1) and the curves recording instrument sensitivity settings.
For example, if only X DATA and Y DATA curves were specified, using the Curve
Select sub-menu, as being required then these would be the only two selections
available.
START/STOP/PAUSE/CONT. keys
In the single graph display mode, acquisition to the curve buffer, and hence display
of data, can be initiated using the Start or Loop
acquisition in the one-shot mode. This causes data to be acquired for the number of
points specified by the curve length control in the Curve Buffer menu and once
complete, acquisition ceases. During data acquisition, the control key annotation
changes to Pause; if pressed again, acquisition will pause at the current data point and
the annotation changes again to Cont. (Continue). If the key is pressed again
acquisition continues from the present data point.
The Loop keys also start data acquisition, but in the loop mode, in which the curve
buffer fills to capacity and is then sequentially overwritten by new data. Once this
mode is running, the Loop control key annotation changes to Stop, and pressing the
adjacent key will then stop acquisition at the present data point.
CURSOR keys
The bottom right-hand
the displayed cursor, which is only active when data is not being stored, from side to
side. The present point number is shown in the bottom right-hand corner of the screen
and the value of the curve at its intersection with the cursor appears in the top right-
hand corner. Where applicable, values are always given as a percentage of full-scale,
since there is no facility to display them in floating-point format. If the cursor is
Chapter 5, FRONT PANEL OPERATION
keys are used to adjust the upper and lower
keys and the and
keys are used to autoscale the
keys. The Start keys start
cursor-movement keys move
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