CML Semiconductor Products
PRODUCT INFORMATION
CM1481
Applications
Selcall in Two-Way Radio
o-Wa
Alarm Systems
Control/Switc
ol/Switching
Remote Control/Switching
Non-Predictive Selcall Module
Obsolete Product
‘For Information Only’
Control
Switching
‘SECURE’ Control and Switching
Control
Industrial Control
Automatic User Identity
5
‘N’-T
ONE
S
ELCALL
E
NCODING
& N
ON
-P
REDICTIVE
D
ECODING
+
5
G
ROUP
C
ALLING
CM1481
Operating
and
Programming
Programming
Manual
Manual
Features
5
Encoding and Non-Predictive
All-Tone Decoding
All-Tone
Low-P
w-Po
5
Low-Power Requirement
D.C.
(4.0mA @ 6v to 26v D.C.
[typ]
)
5
All-System GROUP-Call
GROUP-Call
5
Transponding and ANI
5
Over-Air
“Stun and Release” and
Over-Air
“Re-Configuration”
5
CCIR, EEA and ZVEI Tonesets
5
Simple , Serial Configuration
Simple,
5
Multiple Coded Audio Alerts
5
PTT Time-Out Timer
5
PTT Lockout
Lock
5
Remote Reset Facility
Facility
5
Simple Radio Interface
The CM1481 Non-Predictive Selcall Module
Table of Contents
Introduction to The CM1481
Summary of Standard Functions and Features
Installation Instructions
Power Requirements
Handling Precautions
Alert Audio Levels
Radio Interface
Circuit Diagram
PCB Layout
Configuration
Configuration Menu
Error and Status Messages
Receive Call Operation
Transmit Call Operation
LED Call Memory
LED Drive
Automatic REPEAT-Tone
Timed Mute Reset
Audio Alerts
PTT Lockout
Single or Dual Button Operation
Automatic Number Identification (ANI)
Tx Timeout and Warning
N
OTONE
Timer
Transponding
Input/Output Polarities
Lead-In Tone
Quiet/Open Modes
Lead-In Delay
Over-Air Functions
Power-Up 'Quiet'/'Open'
‘Muted’ Call Initiation
Security Checks
Example Over-Air Transactions
Pseudo-Random Number Information
Over-Air Tone Information
Hexadecimal Sequential Code
Operational Rules
Tone Allocations
International GROUP CALL
Non-International GROUP CALL
Specification
Ordering Information
3
3
4
4
4
4
5
6
7
8
10
11
12
12
12
12
13
13
13
13
14
14
15
15
15
15
16
16
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17
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19
19
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21
21
22
22
22
23
24
2
Brief Introduction to The CM1481
The CM1481 is a compact 5- or 6-Tone CCIR, EEA
and ZVEI selcall module with individual address
encoding, non-predictive all-tone decoding,
transponding and full, all-system GROUP Call and ANI
capabilities.
In addition to normal selcall facilities, the CM1481
offers, as standard, a range of over-air control facilities
to allow a base-station additional control when working
with remote units.
These added facilities are:
‘Stun’ and ‘Release’ - To allow the controller to
completely ‘freeze’ all module and parent radio audio
functions rendering it inoperative until ‘Released’. This
to counter theft, air misuse/abuse or non-payment of
fees.
‘Re-Configuration’ - To change module addresses
and modes via an over-air command. This to allow
unit participation in other user groups.
‘Stun’, ‘Release’ and ‘Re-Configuration’ operations
are carried out using a secure authentication protocol
to prevent accidental or illegal transactions.
The unit may be muted by the base.
Under the control of its on-board µController,
operating from instructions written to it by a simple
menu-driven configuration operation from a basic 'PC'
type computer, the CM1481 can completely control
the workings of the radio's Rx and Tx audio
processes.
After Configuration the only operator inputs
required are Microphone/Handset, Volume and Selcall
Tx/Mute controls.
The CM1481 will detect and decode all incoming
tone information, controlling the radio functions whilst
providing the operator with various coded audio alerts
to indicate status and progress.
J1
/1
3
+
CM1481
D
J1
U
1
-
Configuration Interface Connector
/1
+
X1
U
3
U
2
IN
Fig.1 A Typical Configuration Setup
CM1481 - A Summary of Standard Functions and Features
Configuration by Menu-Driven
Software via a Serial ‘PC’ Link
CCIR, EEA and ZVEI
Toneset/Length Capabilities
HSC Signalling Control Features
Over-Air “Stun” & “Release”
Rapid Over-Air “Re-
Configuration”
Remote Reset
Individual Addressing
Extended Group & Data Tone
Facilities
Simple Radio Interface
Low-Power Requirement
(4.0mA typ)
“Muted” Call Initiation
Programmable I/O Polarities
Lead/Trail Automatic Number
Identification (ANI)
Programmable Lead-In Tone
and Delay
Transponding Facility
Single or Dual Button Operation
Timed Mute Reset
Tx (PTT) Time Out + Warning
PTT (Busy) Lockout
CMOS Compatible Logic
Operators' Coded Call-Alert
Capability
3
O
U
T
-A
U
D
IO
SW
IT
C
H
U
4
Installation
Installation Instructions
The CM1481 is designed to be embodied physically within a mobile, portable or handheld transceiver to interface
electrically with Rx and Tx audio circuitry via the Radio Interface. The diagram below shows the input and output
system functions of the CM1481.
Before Installation it is recommended that this document is studied carefully.
Power Supply
(12)
(5)
PTT IN
GND
V IN
(13)
(4) QUIET/OPEN
(3)
(2)
(1)
Tx CALL
BUSY
CONFIG
Micro-Controller
Regulator
Tx ON
(11)
MUTE CTRL (10)
LED
TONE OUT
ALERT
(8)
(9)
(7)
(6)
SIGNAL IN
Audio
Signalling
Processor
EEPROM
Audio Switch
Fig.2 The Radio Interface
Method of Installation
Ensuring that there is sufficient room to introduce
the Radio Interface lead and the Configuration
Interface Connector, place the CM1481 into its
operating position using the double-sided sticky-pad
(supplied) on the discrete component side of the
module. Ensure that the module adheres firmly to its
mounting surface.
Consider the requirements for Single or Dual
Button operation.
Do not attempt to install the module into areas of
the radio where it may be subject to high RF fields.
Ensure that the CM1481 is well insulated from other
radio components.
It is recommended, at this stage, that some record
is formulated to identify the configuration state of the
module/radio pair.
Handling Precautions
The CM1481, which is supplied in an anti-static
package, contains CMOS devices. It is recommended
that to prevent damage, Electrostatic Discharge
Precautions are employed at all stages of any
production process involving this module.
Alert Audio Levels
If alert levels from the CM1481 are to be fed into
an external audio amplifier it is recommended that the
LINK is removed. Removal of the LINK will allow
connection to high-impedance loads.
LINK IN can drive an external loudspeaker.
LINK OUT can drive an external amplifier.
See layout diagrams, Figure 4, and Table 5 (Audio
Alert Descriptions).
Installation Dimensions
CM1481 board size.
45mm x 22mm x 8mm.
Power Requirements
The supply voltage requirement of the CM1481 is
between 6 and 26 volts d.c.
4
Installation ......
CM1481 Radio Interface
The table below shows the functions and interconnections of the CM1481 interface (J1) employed in both
NORMAL
and
CONFIGURATION
modes.
Functions prefixed by a star (*) indicate configurable IN/OUT polarities. Consult the Configuration section of this
*
manual for Configuration Instructions and Configuration Interface Connector termination information.
Pin
1
2
Function
CONFIG
*
BUSY
Normal Mode - to Radio
Function
Configure Mode - to PC
Configuration mode sense. When this pin is “High” the module WILL NOT enter the
CONFIGURATION
mode, when “Low” the module WILL enter the
CONFIGURATION
mode on power-up.
Input from the radio squelch circuitry. A level here
indicates the presence of an RF carrier.
Input from the installation “Operation” momentary-
action switch to initiate a Selcall.
See "Single/Dual Button" Operation notes.
CLOCK
The CLOCK signal generated by
the configuring PC is input here.
3
*
Tx CALL
4
*
QUIET/OPEN
Input from the installation “Operation” momentary- DATA IN
action switch to control the radio mute state.
See "Single/Dual Button" Operation notes.
Input from the Mic. or peripheral PTT line.
The CM1481 controls the radio Tx function via
Tx On.
Input for received Selcall tones from the radio
demodulator prior to squelch circuitry.
Audible alerts output. Introduce into the radio's Rx
audio stage with due regard to any audio powersave
functions. This output can drive a loudspeaker directly.
Output drive to an LED indicator.
Connect an LED between this pin and GND.
Selcall tone output. Introduce this output into the
radio Tx Audio path.
Connect to radio Rx Squelch circuitry so that when
this output is active Rx Audio is muted.
Tx PTT Drive. When active this output will key the Tx.
Signal Ground (-)
Positive Supply Voltage (+)
Data from the configuring PC to the
module is input here.
5
*
PTT IN
6
SIGNAL IN
7
ALERT
8
*
LED
DATA OUT Data from the module to the
configuring PC is output here.
9
TONE OUT
10
*
MUTE CTRL
11
12
13
*
Tx ON
GND
V IN
AUDIO SWITCH
An on-board (Audio Signalling Processor) all-audio switch-path, accessible via on-board
solder-pads. This switch operates in co-ordination with the QUIET/OPEN function for use with all audio
signals. When 'Quiet' the switch is OFF, when 'Open' the switch is ON.
Table 1 CM1481 Radio Interface Functions
The position of Pin 1 is identified on Figure 4 (PCB Layout).
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