VTI Instruments Metek EX1202 - Page 114

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114 EX1200 Triggering
If a hardware trigger (an LXI, LAN, or DIO line) is selected as either the Scan Trigger or Step
Trigger source, and the Rise/Fall slider will appear. This slider allows the user to choose which
edge polarity will be accepted as the arm or trigger source or which will be asserted as a trigger
output.
FIGURE 7-9: RISE/FALL OPTION FOR HARDWARE EVENTS
If Alarm0 is selected as either the Arm or Trigger source, a Configure button will appear.
Clicking on this button provides the following configuration options:
 Time: Indicates the IEEE 1588 time at which the alarm will begin firing.
 Now button: Clicking this button retrieves the current IEEE 1588 time from the EX1200
system and places it on the Time field.
 Period: Indicates the time, in seconds, to wait between alarm firings.
 Repeat: Indicates the number of times the alarm will fire. A “0” in this field results in infinite
firing.
FIGURE 7-10: ALARM CONFIGURE OPTIONS
Notes on Web Page Use
To create a trigger that repeats at a specified time interval, set one of the trigger inputs to
ALARM0. Then configure the alarm with Time and Repeat set to 0. Now, when Period is
defined, an infinitely running timer is created which triggers at the defined period.
 Step/Scan Complete Out: When each scan step (each row of the scanlist table) is completed,
Step Complete is asserted. When the last step in the scanlist is completed, Scan Complete is
asserted. Use these options to define which trigger lines to assert for these events.
None: When selected, no event is performed upon completion of the scan-step or scanlist.
LXI0 – LXI7: Triggers the selected LXI Trigger bus line at the end of the scan step or
scanlist.
LAN0 – LAN7: Triggers the selected LAN event at the end of the scan step or scanlist.
DIO0 – DIO7: Triggers the selected digital I/O channel at the end of the scan step or scanlist.
 Scan Count: Indicates the number of times the full scan list will be run. This value must be
between 1 and 2,147,483,648. If set to 0 or a negative number, the arm count is infinite.