User`s guide

2 Targets and Scopes in the MATLAB
®
Interface
• If NumPrePostSamples is a positive number, the scope is in a posttriggering
mode, where it starts collecting samples after the trigger event.
The following topics describe two examples of acquiring data:
• “TriggeringOneScopewithAnotherScopetoAcquireData”onpage2-16
— Describes a configuration o f one scope to trigger another using the
concept of pre- and posttriggering
• “Acquiring G ap-Free Data Using Two Scopes” on page 2-19 — Describes
howtoapplytheconceptoftriggering one scope with another to acquire
gap-free data
Triggering One Scope with Another Scope to Acquire Data
This section describes the concept of triggering one scope with another to
acquire data. The description uses actual scope objects and properties to
describe triggers.
The ability to have one scope trigger another, and to delay retrieving data
from the secon d after a trigger event on the first, is most useful wh en data
acquisition for the second scope is triggered after data acquisition f or the
first scope is complete. In the following explanation, Scope 2 is triggered
by Scope 1.
• Assume two scopes objects are configured as a ve ctor with the command
sc = tg.addscope('host', [1 2]);
• For Scope 1, set the following values:
- sc(1).ScopeId = 1
- sc(1).NumSamples = N
- sc(1).NumPrePost Samples = P
• For Scope 2, set the following values:
- sc(2).ScopeId = 2
- sc(2).TriggerMod e = 'Scope'
- sc(2).TriggerSco pe =1
2-16