Measurement Computing DaqBook 2000 Series - Manual (Page 89)

Glossary 959395 G-3
Trigger An event to start a scan or mark an instant during an acquisition. The event can be defined in
various ways; e.g., a TTL signal, a specified voltage level in a monitored channel, a button
manually or mechanically engaged, a software command, etc. Some applications may use pre-
and post-triggers to gather data around an instant or based on signal counts.
TTL Transistor-Transistor Logic (TTL) is a circuit in which a multiple-emitter transistor has replaced
the multiple diode cluster (of the diode-transistor logic circuit); typically used to communicate
logic signals at 5 V.
Unipolar A range of analog signals that is always zero or positive (e.g., 0 to 10 V). Evaluating a signal in
the right range (unipolar or bipolar) allows greater resolution by using the full-range of the
corresponding digital value. See bipolar.