Operation
Page 36
ETIC - MR1200 - USER MANUAL - 908709-02
4.4. Radio channel access, & use of the CCIR/ZVEI tone dialler
4.4.1. Introduction
Two elements comprise the MR1200 "tone dialling" system : the radio carrier detection circuitry and a
tone encoder conforming to CCIR or ZVEI standards.
This system can be programmed to :
•
operate and control carrier activation of a relay conforming to CCIR or ZVEI standards,
•
call paging devices conforming to CCIR or ZVEI standards,
•
or simply test radio channel availability before transmission in order to avoid collisions,
•
.../...
4.4.2. Programming
The choice between CCIR or ZVEI mode is programmable (
st_num
parameter).
The tones to transmit and/or the radio channel access code are defined in a call sequence comprising a
chain of up to 10(max.) ASCII characters chosen from the following symbols :
'
0
' to '
9
'
'
A
' to '
E
'
transmit corresponding tone.
(CCIR or ZVEI mode)
'
:
'
test for channel availability.
(no radio carrier wait time - 6s max.)
'
#
'
test relay carrier activation, follows sequence sent if
carrier present.
(radio carrier present wait time - 6s max.)
'?'
deactivate half duplex then test for presence of relay
carrier. Follows sequence sent if carrier absent. (see
examples below)
'
>
'
enable transmission
'
!
'
disable transmission (receive)
'
,
'
short pause (100 ms)
'
W
'
long pause (2 s)
Examples:
'
:>
'
wait for channel to become free (6s max.),
if channel free - transmit,
if not - report CFIAB failure.
Summary of Contents for MR1200
Page 1: ...MR1200 RADIO MODEM 1200 bauds USER MANUAL 908709 02 AUGUST 2000 ...
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