Chapter 7.
Working in TOP View (Optional Feature)
Acquiring TOP View Data in ENCODED Mode
After the instrument is configured as described in Section 7.1.1 and Section 7.1.3, the TOP View display is not
immediately active when the VIEW MODE Function (in the VIEW Submenu) is set to TOP. Instead, the instrument
acquires data only while the encoder’s wheel is turning. This feature limits collection of TOP View data to only those
time periods during which the probe is moving over the test piece surface. ENCODED operation is shown in Figure 68
on page 153.
Note: While scanning in ENCODED or TIMED mode, TOP View data is first added to the display screen, which
contains data acquired while the scanning the approximate distance listed in the DISPLAY LENGTH Function
box. When the screen is full, as it is in Figure 68, the initial data “scrolls” into the instrument’s data buffer.
When the buffer is full the scanning process automatically stops, requiring the operator to take action before
the data is overwritten. At any time, the TOP View scanning process can be stopped, allowing on-screen and
buffered data to be stored. Storing the data in a data set erases the data buffer. Therefore, if analysis and
review of acquired data is to be performed directly on the instrument, it should be accomplished before the
data set is stored (Section 7.4).
Note: The TOP View quadrature encoder controls the collection of TOP View data in two ways. First, data is only
collected while the encoder wheel is turning (i.e., while the probe is moving over the test piece). Second, the
encoder allows data to be overwritten when its direction of travel is reversed. For instance, moving the probe
and encoder forward over a distance of 10 cm, then reversing the probe’s movement by 2 cm, will cause the last
2 cm of forward-moving data to be replaced by the 2 cm of reverse-moving TOP View data.
Accessing the TOP View Control Menu
When TOP View mode is initiated, the Knob Emulator/ TOP View Control Menu is displayed. While this menu is
displayed, the knobs are disabled. In TIMED mode, parameters can be adjusted by pressing below KNOB+ or
KNOB-. Pressing any other non-menu key (such as ) enables the knobs and “hides” the TOP View Control Menu.
While acquiring data in ENCODED mode, only the key below STOP is enabled.
While operating in TOP View mode, pressing switches the display’s menu bar from any currently active menu to
the Knob Emulator/TOP View Control Menu. This menu, shown in Figure 68 on page 153, allows the screen to be
frozen by pressing below STOP, or (in TIMED mode only) cleared by pressing below CLEAR. It also allows the
display to be cleared and restarted or to resume data collection from the point at which it was stopped. See Section 7.3
to work with a frozen TOP View Display or Section 7.4 to store the acquired TOP View data in a data set.
Selecting the TOP View DATA SOURCE
At any time when operating in TIMED mode (or when the display is frozen in ENCODED mode), the displayed TOP
View data can be modified using the DATA SOURCE Function (accessed via the VIEW Submenu in the DISPLAY
Menu). Note that options include:
AMP A – Amplitude of A-Scan echo triggering A-Gate
AMP B – Amplitude of A-Scan echo triggering B-Gate
TOF A – Sound path distance to A-Gate triggering echo
TOF B – Sound path distance to B-Gate triggering echo
152 Phasor XS User’s Manual
