Using Scream!
5.1.5 Level triggering
Using the
Level
triggering method, a trigger is generated whenever one of the
checked components reaches a certain level above the baseline. You can select
which tap is monitored from the
Data source
drop-down menu, and the channel(s) to
be considered from the
Channel
column of the table. The values in the
Level
column
are the number of counts above the baseline that channel must reach before a trigger
is generated.
As with the
STA/LTA
method, the values of the
Level
will often be the same for all
checked channels. If you want to use different values for some channels, you should
clear the Common values check-box before altering them.
Once you have enabled the
Level
triggering method on a particular channel, you can
use the
Control
window to change the level at which the system triggers without
restarting the digitiser.
5.1.6 External triggering
When a digitiser or digital sensor triggers, it signals the fact to connected devices, as
well as sending any extra data that it has been configured to transmit. You can
configure other digitisers to respond to this signal by triggering in turn. This is an
option which you can specify at the time of manufacture. See Section 7.4 on page
106, for details of how to set up an installation for external triggering.
As an example, to instruct a stand-alone digitiser with digital inputs to respond to
triggers generated by an attached digital sensor:
1. Open the
Configuration setup
window for the digital sensor, and check
Enable
External Trigger Output
- this causes it to send triggers to connected devices;
2.
UPLOAD
the new configuration to the digital sensor;
3. Open the
Configuration setup
window for the digitiser, and check
Enable
External Trigger Input
- this causes it to listen for triggers coming from the
digital instrument, and to record data from any attached analogue
instruments when it receives one (depending on its
Output control
configuration); then
4.
UPLOAD
the new configuration to the digitiser.
If a digitiser has both
Enable External Trigger Output
and
Enable External Trigger
Input
selected, it will record data when it receives an external trigger as if it had
triggered itself, but it will
not
relay the trigger on to other digitisers. It will only
send a trigger message if its
own
triggering criteria are satisfied. This prevents
triggering loops.
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Issue U - December, 2021
