User's Manual

Table Of Contents

TB7100 Installation and Operation Manual Glossary 133

FFSK FFSK (fast frequency shift keying). In Trunking applications this is the

method by which code words are sent over the control channel. In 1200

baud FFSK, a 1200 Hz tone represents a zero and an 1800 Hz tone

represents a one.

frequency band The range of frequencies that the equipment is capable of operating on.

front panel The part of the chassis that has the user interface on it.

Full Duplex Full duplex is the action of receiving and transmitting at the same time.

function key A function key is a key on a radio or radio accessory that can have functions

assigned to it.

gating Gating is the process of opening and closing the receiver audio path. When

a valid signal is received, the receiver audio path opens.

GPIO General Purpose Input Output (GPIO) lines are used on the TB7100 to

configure it for different modes.

hysteresis Hysteresis is the difference between the upper and lower trigger points. For

example, the receiver gate opens when the upper trigger point is reached,

but will not close until the level falls to the lower trigger point. An adequate

hysteresis prevents the receiver gate from repeatedly opening and closing

when the level is about that of the trigger point.

inactive Digital outputs are inactive if the base station is doing nothing to them. They

are floating, open collector outputs. Digital inputs are inactive when they are

open circuit.

indicator Indicators provide feedback to the radio user on how the current operation

is proceeding and on the operating state of the radio. For example, keypress

confidence tones are the tones heard when a keypad key or a function key

is pressed and tell the user that an action is permitted. Tait radios use

combinations of audible indicators and visual indicators.

inhibit Prevents the radio state changing.