Glossary, I/o port – Horner APG QX751 OCS User Manual
Page 36
CH. 8
MAN0890-02-EN
August 20, 2009
Page 36 of 96
ECN # 979
8.2 Glossary
Table 8.2 – Glossary
Accumulator
Register used to accumulate or store up a sum or count of many items or events.
Clear
A special function to zero out the value in a specific register. (Not used with Frequency
Counter.)
Disable
A special function to trigger counter to stop.
Encoder
A sensor or transducer for converting rotary motion or position to a series of electronic pulses
Frequency
Input
The number of times an electromagnetic signal repeats an identical cycle in a unit of time,
usually one second.
Latch
(strobe)
A special function that uses a digital logic circuit to store one or more bits. A latch has a data
input, a clock input and an output. When the clock input is active, data on the input is "latched"
or stored and transferred to the output register either immediately or when the clock input goes
inactive. The output retains its value until the clock goes active again.
Marker
Indicate a particular position on a display surface or a value in an instrument.
Polarity
A Polarity pull-down box is associated with each function and indicates the manner in which
the trigger happens (e.g., High level, Low Level, Falling Edge, Rising Edge).
Preload
(load)
A special function used to trigger loading of a value into a register upon an event. (Not used
with Frequency Counter.)
Quadrature
A high speed device that expresses the phase relationship between two periodic quantities of
the same period when the phase difference between them is one fourth of a period. A coupler
in which the two output signals are 90° out of phase.
Totalizer
A counter that sums the total number of cycles applied to its input.
8.3
I/O Port
Figure 8.1 – I/O Port (HSC/PWM) Terminal Connector
PIN 12
PIN 2
PIN 1