Agilent Technologies L4400 manual Trigger Count, Externally Triggering a Scan

Operating and Programming 3

Note: To stop a scan, send the ABORt command.

Externally Triggering a Scan

In this configuration, the instrument sweeps through the scan list once each time a low- going TTL pulse is received on the rear- panel Ext Trig Input line (pin 6).

•You can specify a scan count which sets the number of external pulses the instrument will accept before terminating the scan. See “Trigger Count” for more information.

•If the instrument receives an external trigger before it is ready to accept one, it will buffer one trigger and then ignore any additional triggers received (no error is generated).

•All readings from the scan are stored in volatile memory. Readings accumulate in memory until the scan is terminated (until the scan count is reached or until you abort the scan).

•Mx+B scaling and alarm limits are applied to measurements during the scan and all data is stored in volatile memory.

The following program segment configures the instrument for an external scan.

TRIG:SOURCE EXT	Select external mode
TRIG:COUNT 2	Sweep the scan list 2 times
INIT	Initiate the scan

Note: To stop a scan, send the ABORt command.

Trigger Count

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 specify the number of triggers that will be accepted by an instrument before returning to the “idle” state. The trigger count applies to both scanning and non- scanning applications.

• Select a trigger count between 1 and 500,000 triggers, or continuous.

L4400 User’s Guide 75