Setting Up The Trigger System; Arm And Trigger Sources - HP E1419A User Manual

Setting up the Trigger System

Arm and Trigger
Sources
Selecting the
Trigger Source
78 Programming the HP E1419A
Overflowed), and an error message is put in Error Queue (read with
SYS:ERR? command).
•
Overwrite; When the FIFO fills, the oldest values in the FIFO are
overwritten by the newest values. Only the latest 65,024 values are
available. In OVERwrite mode the module must be halted (ABORT
sent) before reading the FIFO (see "Reading the Latest FIFO Values"
on page 3-86). This mode is very useful when you want to view an
algorithm's response to a disturbance.
To set the FIFO mode (blocking is the *RST/Power-on condition):
[SENSe:]DATA:FIFO:MODE OVERWRITE
[SENSe:]DATA:FIFO:MODE BLOCK
Figure 3-7 shows the trigger and arm model for the HP E1419A. Note that
when the Trigger Source selected is TIMer(the default), the remaining
sources become Arm Sources. Using ARM:SOUR allows you to specify an
event that must occur in order to start the Trigger Timer. The default
Arm source is IMMediate (always armed).
Figure 3-7 Logical Arm and Trigger Model
In order to start an algorithm execution cycle, a trigger event must occur.
The source of this event is selected with the TRIGger:SOURce <source>
command. The following table explains the possible choices for <source>.
select overwrite mode
select blocking mode
Chapter 3