Scan trigger source, Interval scanning – Agilent Technologies L4400 User Manual
Page 84
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L4400 User’s Guide
3
Operating and Programming
Scan Trigger Source
Usage:
•
L4421A 40- Channel Armature Multiplexer
•
L4450A 64- Bit Digital I/O (digital input, counter channels only)
•
L4452A Multifunction Module (digital input, totalizer channels only)
You can configure the event or action that controls the onset of each
sweep through the scan list (a sweep is one pass through the scan list):
• You can set the instrument’s internal timer to automatically scan at a
specific interval. You can also program a time delay between channels
in the scan list (see
• You can start a scan when an external TTL trigger pulse is received.
• You can start a scan when an alarm event (L4450A, L4452A) is logged
on the channel being monitored.
Interval Scanning
In this configuration, you control the frequency of scan sweeps by
selecting a wait period from the start of one trigger to the start of the
next trigger (called the trigger- to- trigger interval). If the scan interval is
less than the time required to measure all channels in the scan list, the
instrument will scan continuously, as fast as possible (no error is
generated).
Figure 3-10. Trigger-to-Trigger Interval.
• You can set the scan interval to any value between 0 seconds and
99:59:59 hours (359,999 seconds), with 1 ms resolution.
• Once you have initiated the scan, the instrument will continue
scanning until you stop it or until the trigger count is reached. See
on page 75 for more information.
t
Sweep 1
Trigger 1
Sweep 2
Sweep
n
Trigger 2
. . .
Trigger Timer
(0 to 359,999 seconds)