HP 437B - Page 31

HP 437B
eS
Table
8-2.
Schematic
Diagram
Notes
(8
of
8)
DIGITAL SYMBOLOGY REFERENCE INFORMATION
Miscellaneous
Schmitt Trigger—Input characterized by hysterisis; one threshold for positive
going signals and a second threshold for negative going signals.
Active State—A binary physical or logical state that corresponds to the true state of
an input, an output, or a function. The opposite of the inactive state.
Enabled Condition—A logical state that occurs when dependency conditions are
satisfied. Although not explicitly stated in the definitions listed above, functions
are assumed to be enabled when their behavior is described. A convenient way to
think of it is as follows:
A function becomes active when:
¢ it is enabled (dependency conditions—if any—are satisfied)
© and its external stimuls (e.g., voltage level) enters the active state.
SERVICE —8-13/8-14