Olympus EPOCH 650, User Manual, Page: 145 / 362

DMTA-10055-01EN, Rev. A, February 2015
Gates 133
3. Position the gate to the desired position.
4. Press Zoom (P1 key) to zoom in.
5. Press Zoom again to zoom out (default view).
Zoom can only be active for one gate at a time.
7.8 Gate Alarms
The EPOCH 650 ultrasonic flaw detector features a variety of alarm configurations for
each measurement gate. In unrectified (RF) mode, these alarms can be used in
positive, negative, or dual gate modes.
By default, when an alarm condition is triggered, the EPOCH 650 emits an audible
beep. The instrument also illuminates the red indicator, above the display window,
corresponding to the gate with which the alarm has been triggered. To toggle the
audible alarm on and off, see “General Setup Page” on page 95.
The three primary types of gate alarms are positive threshold, negative threshold, and
minimum depth.
When an alarm condition is triggered on a particular gate, the corresponding alarm
output pin on the Digital Out connector provides a 5V TTL signal. For more
information, see “Alarm Outputs” on page 137.
7.8.1 Threshold Alarms
Threshold alarms can be set on gate 1 or gate 2.
A positive logic alarm is triggered when a signal breaks the gate threshold. A negative
logic alarm is triggered when a signal drops out of the gate threshold.
When you set a threshold alarm, the appearance of the tick marks at the end of the
gate changes. For positive logic alarms, the tick marks point upward and for negative
logic alarms they point downward (see Figure 7-8 on page 134). All alarm conditions
are stored in the EPOCH 650 data logger when the gate alarm is active and triggered
at the time of file storage. All saved IDs with an active alarm display A1 for gate 1
alarm, A2 for gate 2 alarm, or AIF for interface gate alarm.