Agilent Technologies HP 1660E Series User Manual page 339

Logic Analyzer Reference
The Analyzer Trigger Menu
One possible scenario is to have several test instruments and a logic
analyzer connected to a complex target system. The analyzer is armed
by an external Arm In signal from another test/measurement entity.
After the first analyzer triggers, it arms the second analyzer. After the
second analyzer triggers, it sends a Port Out signal through the
external BNC. This signal is used to arm another external test/
measurement entity.
The Arm Out signal can be generated by either one of the two local
analyzers.
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