Measurement Computing IOtech 640 Series - Manual (Page 99)

640 & 650 Series 907493 Glossary G-3
Trigger For IOtech 640 and 650 Series devices, “trigger” refers to a software event that starts a scan or
marks an instant during an acquisition.
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.