CPX2 [RADIOMETRIX]

2700 baud wireless packet modem;


型号：	CPX2
厂家：	RADIOMETRIX LTD
描述：	2700 baud wireless packet modem 传感器换能器半导体
文件：	总7页 (文件大小：108K)
中文：	中文翻译
下载：	下载PDF数据表文档文件

Hartcran House, 231 Kenton Lane, Harrow, Middlesex, HA3 8RP, England

Tel: +44 (0) 20 8909 9595, Fax: +44 (0) 20 8909 2233, www.radiometrix.com

Issue 1, 15 September 2015

PRELIMINARY

CPX2

2700 baud wireless packet modem

The CPX2s a 2,700 baud half-duplex serial radio

packet modem module operating on licence-

exempt European 433.05-434.79MHz SRD band.

CPX2 is an intermediate level OEM radio

modem which is in between a raw FSK radio

module like BiM2G and a sophisticated OEM

radio modem like RPM2A. It takes care of

preamble, frame synchronisation and error

checking.

Features

Figure 1: CPX2-433.92-2k7

. Conforms to EN 300 220-2 and EN 301 489-3

. SAW front-end filter

. Small size

. Low cost

. Direct interface to microcontroller UART

. Serial modem baud rate at 2,700bps (half-duplex)

. 200m line of sight operating range

Applications

. Home/Industrial Automation

. Vehicle Sensor Monitoring

. Telemetry

. Data Logging Systems

. Security Systems for Home/Industrial

. In-building environmental monitoring and control

. Sports and Performance Monitoring

Technical Summary

. Operating frequency: 433.92MHz (default)

. Modulation: 2.7kbps NRZ FSK

. UART interface: 57,600bps, 8 data bits, Parity None, Flow Control None

. Supply: 3.3V at 23mA transmit, 13mA receive and <2mA standby

. Transmit power: +3dBm (2mW)

. Receiver sensitivity: -105dBm (for 0.1% data error)

. 32 byte data buffer

. 40 x 14 x 5mm

Radiometrix Ltd

CPX2 Data Sheet

page 1

Radiometrix Ltd

CPX2 Data Sheet

page 2

Operation of the CPX2 packet data transceiver

The CPX2 is a variant of the basic CLX2 data link device, using the same hardware but achieving

considerably greater range (albeit at the cost of a lower aggregate data rate). On the other hand, Its user

interface data rate is considerably faster (57,600 baud) to minimise data transfer time overhead to and from

the module, so in some applications the CPX2 will actually exhibit better efficiency.

While a standard CLX2 will reliably receive a -95dBm signal, the CPX2 is reliably seen to recover packets at

signal levels of -105dBm and less (corresponding to around twice the range).

The CPX2 is not a transparent modem. It cannot handle constant streaming data.

All timing and data formatting tasks are handled by the software. The user need not worry about keying the

transmitter before sending data. For transmission across the radio link data is formatted into packets, each

comprising data bytes, preamble sequence, frame synchronisation code and checksum.

It sends its data in discrete 32 byte blocks, and while it is sending a block it cannot do anything else.

A 32 byte block (or "packet") takes about 150ms to send (during which the RF carrier is 'on' for 140ms)

The unit idles in receive. If a valid RF packet is detected, then it is immediately decoded and outputted as a

stream of serial data bytes (start bit following preceding stop bit)

If data is presented to a unit's TXD pin, the first byte received initiates the transmit process. The unit will

immediately switch its RF circuits from receive to transmit and start loading any available transmit data into

its buffer. It will carry on loading the buffer until either:

1. 32 bytes are received, or

2. A gap of 5ms is seen following a byte.

At this point the unit pulls the active low TXON pin low and begins modulating its carrier (by now stabilised

and at full power) with the coded data packet. Any "extra" bytes beyond the first 32 are discarded.

Once the burst has been transmitted, the transmitter turns off and TXON is returned to the high state.

In the absence of a valid signal, the CPX2 (in idle/receive) uses framer and checksum data to avoid

outputting random garbage. Similarly, at the edge of the range or in the presence of interference the unit will

either output complete, correct data blocks or nothing at all (it is very unlikely to ever output a corrupted

block)

Pulling the /RXOFF pin low (against its internal pull-up) puts the unit into standby (as on the CLX2)

Figure 3: CPX2 footprint (top view)

Radiometrix Ltd

CPX2 Data Sheet

page 3

Pin description

Name

GND

Function

Ground

RXD

TXD

/TXON

/RXOFF

Received Data output at 3V UART (inverted RS232) level

Transmit Data input at 3V UART (inverted RS232) level [No pull-up]

/TXON Active low Transmitter ON indicator Output [Transmit Mode]

/RXOFF Active low Receiver hot Standby Input [Receive Mode]

Open drain, 50k internal pull-up

VDD

RSSI

3.3V DC (externally regulated power supply)

Received Signal Strength Indicator output

(An optional pad for wire connection)

RF in/out (50 impedance)

RFGND

RF Ground

Notes:

1. TXD has no internal pull-up. If the unit is used in Receive only mode, tie this pin to VCC

2. VDD must be a clean 3.3V DC regulated supply

3. The STATUS pin. In transmit, this pin pulls low if the device is transmitting a data packet.

On receive it floats high. If pulled low in receive, the unit goes into hot standby (<2mA)

In standby the unit does not receive, but will go into transmit if valid data is presented to TXD.

4. TXD / RXD are inverted RS232 at 3V CMOS levels. To connect to a true RS232 device, inverting

level shifters must be used (e.g. MAX232 type are ideal, but simple NPN transistor switches with

pull-ups often suffice). With typical microcontrollers and UARTs, direct connection is possible.

5. Because CPX2 provides a lower 2,700 baud half duplex radio link with higher 57,600 user baud rate,

no more than 32 bytes should be uploaded at a time. i.e. data cannot be streamed.

6. Provided no two devices attempt to transmit at one time, then no further restrictions on data

transmission need be made, as all transmit timing, valid data identification and data byte buffering is

conducted by the unit. There is no 'transmit enable' pin. Synchronisation and framing words in the

packet prevent the receiver outputting garbage in the absence of signal or presence of interference.

7. A 2.2k resistance is present from RF pin 1a to ground for ESD protection

Radiometrix Ltd

CPX2 Data Sheet

page 4

Condensed specifications

Frequency

433.92MHz

Frequency stability

Channel width

Number of channels

Supply Voltage

Current

±10kHz

250kHz

3.3V DC

23mA transmit

13mA receive/

<2mA standby

Operating temperature

Spurious radiations

Interfaces

-20^°C to +55^°C (Storage -30^°C to +70^°C)

Compliant with ETSI EN 300 220-2 and EN 301 489-3

User

5pin 0.1" pitch molex (pin 6 absent)

2pin 0.1" pitch molex

Size

40 x 14 x 5mm

Transmitter

Output power

TX on switching time

Modulation type

FM peak deviation

TX spurious

2mW ±1dB

<4ms

2.7kbps NRZ FSK

+/-30kHz (nominal)

<-36dBm

Receiver

Sensitivity

Blocking

-105dBm (for 0.1% data error)

-50dB (±1MHz)

Local Oscillator re-radiation

<-57dBm

Interface

Data rate

Format

Levels

Buffers

57,600baud, Half duplex

1 Start bit, 8 Data bits, No parity, 1 Stop bit

3V CMOS (inverted RS232 ‘0’=0V, ‘1’=3V)

32 byte FIFO

Flow control

Initial start up

None

10ms from power on

Radiometrix Ltd

CPX2 Data Sheet

page 5

Antenna requirements

Three types of integral antenna are recommended and approved for use with the module:

A) Whip

This is a wire, rod ,PCB track or combination connected directly to RF pin of the module.

Optimum total length is 16cm (1/4 wave @ 433MHz). Keep the open circuit (hot) end well

away from metal components to prevent serious de-tuning. Whips are ground plane

sensitive and will benefit from internal 1/4 wave earthed radial(s) if the product is small and

plastic cased

B) Helical

C) Loop

Wire coil, connected directly to RF pin, open circuit at other end. This antenna is very

efficient given it’s small size (20mm x 4mm dia.). The helical is a high Q antenna, trim the

wire length or expand the coil for optimum results. The helical de-tunes badly with proximity

to other conductive objects.

A loop of PCB track tuned by a fixed or variable capacitor to ground at the 'hot' end and fed

from RF pin at a point 20% from the ground end. Loops have high immunity to proximity de-

tuning.

whip

***

helical

***

loop

Ultimate performance

Easy of design set-up

Size

***

Immunity proximity effects

The antenna choice and position directly controls the system range. Keep it clear of other metal in the

system, particularly the 'hot' end. The best position by far, is sticking out the top of the product. This is often

not desirable for practical/ergonomic reasons thus a compromise may need to be reached. If an internal

antenna must be used, try to keep it away from other metal components, particularly large ones like

transformers, batteries and PCB tracks/earth plane. The space around the antenna is as important as the

antenna itself.

0.5 mm enameled copper wire

close wound on 3.2 mm diameter former

433 MHz = 24 turns

A. Helical antenna

Feed point 15% to 25% of total loop length

track width = 1mm

RF-GND

4 to 10 cm²inside area

B. Loop antenna

16.4cm

wire, rod, PCB-track or a combination

of these three

433 MHz = 16.4 cm total from RF pin.

C. Whip antenna

Figure 4: Antenna types

Radiometrix Ltd

CPX2 Data Sheet

page 6

Radiometrix Ltd

Hartcran House

231 Kenton Lane

Harrow, Middlesex

HA3 8RP

ENGLAND

Tel: +44 (0) 20 8909 9595

Fax: +44 (0) 20 8909 2233

sales@radiometrix.com

www.radiometrix.com

This product data sheet is the original work and copyrighted property of Radiometrix Ltd. Reproduction in

whole or in part must give clear acknowledgement to the copyright owner.

Limitation of liability

The information furnished by Radiometrix Ltd is believed to be accurate and reliable. Radiometrix Ltd

reserves the right to make changes or improvements in the design, specification or manufacture of its

subassembly products without notice. Radiometrix Ltd does not assume any liability arising from the

application or use of any product or circuit described herein, nor for any infringements of patents or other

rights of third parties which may result from the use of its products. This data sheet neither states nor

implies warranty of any kind, including fitness for any particular application. These radio devices may be

subject to radio interference and may not function as intended if interference is present. We do NOT

recommend their use for life critical applications.

The Intrastat commodity code for all our modules is: 8542 6000

R&TTE Directive

After 7 April 2001 the manufacturer can only place finished product on the market under the provisions of

the R&TTE Directive. Equipment within the scope of the R&TTE Directive may demonstrate compliance

to the essential requirements specified in Article 3 of the Directive, as appropriate to the particular

equipment.

Further details are available on The Office of Communications (Ofcom) web site:

http://stakeholders.ofcom.org.uk/spectrum/technical/rtte/

Information Requests

Ofcom

European Radiocommunications Office (ERO)

Peblingehus

Riverside House

Nansensgade 19

2a Southwark Bridge Road

London SE1 9HA

Tel: +44 (0)20 7981 3000

Fax: +44 (0)20 7981 3333

www.ofcom.org.uk

DK 1366 Copenhagen

Tel. +45 33896300

Fax +45 33896330

ero@ero.dk

www.ero.dk

CPX2 [RADIOMETRIX]

相关型号：

CPX233A

CPX234A

CPX253A

CPX254A

CPX303A

CPX303D

CPX30A

CPX30AF

CPX30D

CPX30DF

CPX30G

CPX30GC