Agilent Technologies L4400 manual Scan Trigger Source, Interval Scanning

3Operating 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 “Channel Delay" on page 77).

•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).

Trigger 1	Sweep 1	Sweep 2		Trigger 2
			Sweep	n
		. . .
				t
		Trigger Timer
	(0 to 359,999 seconds)

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 “Trigger Count" on page 75 for more information.

72 L4400 User’s Guide