FRS Signalling Processor
CMX882
Signalling:
XTCSS
A state-of-the-art (squelch) signalling format, employing both sub-audio (CTCSS) and in-band (XTC)
signalling concurrently, which offers more than twice as many privacy codes as standard CTCSS
operation and completely eliminates interference caused by other traffic on the channel (quiet operation).
Additionally the XTCSS signalling can be employed as an over-air control for such features as voice-
compression. XTCSS is fully compatible with both conventional and enhanced CTCSS signalling
operations and will implement the All Call Code function.
CTCSS
’Zero talkdown’ performance eliminates unwanted breaks in communication. The CMX882 is pre-
programmed with 39 standard CTCSS (+ Notone and DCS ‘turn off’ tone) and 12 additional ‘split-tone’
frequencies. Any one of these can be selected for reception or transmission. Decoding is aided by the
use of adjustable decode bandwidths and threshold levels. Decoding is carried out rapidly thus avoiding
the loss of the beginning of speech or data signals. A CTCSS configuration of this product enables ‘Tone
Cloning’.
Two unique features of this product are its CTCSS ‘All Call Code’ and ‘All Codes Monitor’ modes:
All Call Code – transmissions using this code will be heard by all CMX882 enhanced radios regardless of
their selected CTCSS code. This provides an important benefit to both safety and convenience.
All Codes Monitor – selection of this code at the receiver enables all transmissions that are using a
CTCSS tone to be heard, and the tone number to be reported. Open channel noise or calls lacking
coding, will go unheard. This is a superior method of ‘channel monitoring’, which allows miscoded calls
from conventional CTCSS-party radios to be heard and directly responded to.
2004 CML Microsystems Plc
4
D/882/7
CMLMICRO [ CML MICROCIRCUITS ]
