Warwick X7200 User manual

WARWICK WIRELESS
WARWICK WIRELESSWARWICK WIRELESS
WARWICK WIRELESS
LIMITED
LIMITEDLIMITED
LIMITED
X7200/X7200HP SYNTHESISED RADIO MODEM
WARWICK WIRELESS LIMITED
THE MANOR, ASTON FLAMVILLE, LEICESTERSHIRE, LE10 3AQ ENGLAND
TEL: [phone] FAX: [phone] WEB: www.radiotelemetry.co.uk

INDEX
1.0 FEATURES
2.0 SPECIFICATION
2.1 Radio
2.2 Modem
2.3 Power Supply
2.4 Mechanical and Environmental
3.0 CONNECTIONS
3.1 9 Way D Connector
3.2 LED Indicators
4.0 OPERATION
5.0 GETTING STARTED
5.1 Basic Connections
5.2 Power Connections
5.3 Factory Settings
5.4 Plug and Play
6.0 CONFIGURATION
6.1 Configuration Menu by Hard Wire Link
6.2 Configuration Menu by Terminal Access
6.3 Baud Rate Setting
6.4 Parity On/Off
6.5 Odd or Even Parity
6.6 Repeater Modes
6.6.1 Open Repeater (Echo back mode)
6.6.2 Chain Repeater
6.7 Error Correction
6.8 Address Modes
6.8.1 Basic configuration
6.8.2 Station addressing
6.8.3 Global addressing
6.9 RF Channel
6.10 Transmitter Key
6.10.1 RF power output
6.10.2 ERP and SWR
6.10.3 Antenna alignment
6.10.4 Site surveys
6.11 Transmission Speed
7.0 RADIO TRANSMISSION
7.1 Radio Frequency
7.1.1 DIL Switch Settings
7.1.2 Serial Port Channel Change
7.2 RF Power Adjustment
7.3 Radio Propagation
7.4 Antennas
7.4.1 Helical Antennas
7.4.2 End Fed Dipoles
7.4.3 Yagi Antennas

8.0 TROUBLE SHOOTING
8.1 No Data Transmission
8.2 No Data Reception
8.3 Corrupt Data
8.4 Radio Path
8.5 Help Line Number
9.0 WARNING

X7200/X7200HP RADIO MODEM
1.0 FEATURES
• Type approved for licence free use.
• 17 selectable radio channels.
• Range 10Km to 20Km line of sight and 1Km to 3Km in buildings
• Serial Interface with baud rates of 1200 to 19200.
• RS232 flow control for duplex operation
• Two data transmission speeds.
• 4K of buffer memory.
• Two data repeater modes to extend range.
• Addressable individually and globally
• On-line AT commands for modem dial-up operation and RF channel change.
• Predictor/Corrector error checking mode
• Transmitter keying for site surveys and antenna alignment.
• Low power mode
The X7200 Radio Modem transmits and receives half duplex serial data at baud rates of
1200 to 19200 by means of a FM Radio Transceiver operating on the UK licence except
458.500MHZ to 458.950MHZ band and most other world wide data frequencies - The radio
conforms to MPT1329 and the European ETSI 300-220 standards.
A 4K buffer memory is provided so that data can be passed asynchronously between the
host and modem without the need for handshaking. The CTS output signal can be used for
flow control in duplex applications. It indicates to the host that the RF channel is in use or that
the buffer memory is full. The X7203 interface unit is available if large computer files need to
be transferred with full duplex operation. This add-on unit will provide data packeting, data
encryption and data packet retries.
The over air data speed can be configured at either 5K bits/sec or
10K bits/sec. This is independent of the baud rate and should be set to a lower value were
possible for the best results.
All the parameters on the X7200 radio modem can be set by an internal menu selected by
connecting pin 6 on the 9 way D Connector to 0v or typing $ ESC directly after the power has
been applied. The menu configuration is permanently stored on EEPROM.
A modem can be used in an open configuration in the same way as a RS485 bus or given a
unique transmitter and receiver address. If the address mode is selected only modems with
the same address can communicate with each other. In addition “AT” commands can be
sent to the modem to change the address configuration during normal operation so that any
modem can “dial up” any other modem. These commands are used in specific ways and do
not restrict the use of any data strings or combinations of data.
A forward error correcting algorithm can be configured to increase the integrity of the data
transmission at high speed or over long distances.
The modem can be configured in two repeater modes. The first mode will command any
modem in range to repeat back the data it has just received thereby testing data integrity and
radio range. The second repeater mode uses the address mode to form repeater chains
thereby extending the range of a transmission over physical obstacles or in shaded areas.
The RF frequency is set by the menu, or DIL switches located inside the modem, or by an

“AT” command sent to the serial port. The RF power output can be set from 5mW to 500mW
by a potentiometer also located inside the case. The modem can be configured to transmit a
continues RF carrier so that a site can be surveyed to find the best reception locations and
antenna installations can be correctly aligned and tested.
The X7200 radio modem is powered from a regulated DC source of between 8.5v to 14V. In
receive mode it will take 80mA and in transmit 330mA. Taking DTR low will switch the
modem into a power saving stand-by mode. In this state it will consume approximately 0.1
mA. It will take approximately 20mSec for the modem to become fully operational after DTR
is taken high or power is applied. The modem is protected by an internal resetable fuse.
The modem is housed in a robust, lightweight aluminium enclosure measuring 114mm by
65mm by 26 mm.
Additional options include:
X7201 12V power supply.
X7202 PC to Modem cable.
X7204 IP67 enclosure.
X7205 Leather carrying case.
X7206 Belt mounted battery packs.
X7207 600 ohm line interface module.
2.0 SPECIFICATION
2.1 Radio
RF Frequency 400MHz - 480MHz
RF Power: X7400 5mW
X7200 5mw – 500mW
X7200HP 1W – 12W
Channels 17
Channel Separation 25KHz / 12.5KHz
Modulation F3D. F1D
Receiver Sensitivity 0.3µV for 10dB SINAD
Antenna Connector BNC/TNC
2.2 Modem
Interface Baud Rate
(standard) 19200, 9600; 4800, 2400, 1200
(extended) 600, 300, 150
Data Word 8 bits
Parity Odd, even, None
Stop Bits 1
Modulation Gaussian Minimum Shift Keying
Interface RS232/RS422
Transmission speed 10Kbits/sec, 5Kbits/sec
2.3 Power Supply
DC Supply Voltage 8.5V to 14V (12V nominal)
DC Supply Current
X7200
Transmitting 330 mA
Receiving 80 mA
Stand By 0.l mA

X7200HP
Transmitting @ 1W 870 mA
Transmitting @ 5W 2.8A
Receiving 120 mA
2.4 Mechanical and Environmental
Size without base plate 114mm by 65mm by 26mm
Size overall 140mm by 65mm by 26mm
Operating Temperature
Range -10 to +55 deg C
3.0 CONNECTIONS
3.1.1 9 Way D Type Connector RS232
1 +12V INPUT
6 CONFIGURATION MODE INPUT
2 RD DATA INPUT
7 RTS REQUEST TO SEND INPUT
3 TD DATA OUTPUT
8 CTS CLEAR TO SEND OUTPUT
4 DTR (STANDBY) INPUT
9RSSI OUTPUT
5 0v INPUT
PIN 1+VE 12V regulated power supply, capable of supplying 0.3Amps and an inrush
current of 0.7Amps for 20mSec. It is not advisable to use a switched mode
power supply either to drive the X7200 radio modem or in close proximity to
it. This type of power supply can produce high energy radio frequencies over
a broad spectrum thereby causing interference to the received signal.
PIN 2 RD Receive serial data from host
PIN 3 TD Transmit serial data to host.
PIN 4 DTR A signal of between 0v to -15v will switch the modem into standby power
mode. The input has an impedance of 22Kohms. Open circuit for normal
operation.
PIN 5 OV Power supply and common for host.
PIN 6 CON Configuration input. Connecting 0V to this input will send the configuration
menu to the host when the power is applied. It is left open circuit for normal
operation
PIN 7 RTS Used in curtain applications to inhibit data from the TD output of the modem.
PIN 8 CTS Brought low by the modem when a RF carrier is detected or the receiver
buffer memory is full. This can be connected to RTS on the host to inhibit
data from the host in duplex operations.
PIN 9 RSSI The relative signal strength indication provides a voltage which is
logarithmically proportional to the receiver signal strength.
0V = No RF signal strength
0.7V = 1µV “ “ “
1.6V = 10µV “ “ “
2.4V = 100µV “ “ “
2.7V = 1mv “ “ “

3.1.2 9 Way D Type Connector RS485
1 +12V INPUT
6 CONFIGURATION MODE INPUT
2 DATA IN RS485 IN INPUT
7 DATA IN RS485 IN INPUT
3 DATA OUT RS485 OUT OUTPUT
8 DATA OUT RS485 OUT OUTPUT
4 DTR (STANDBY) INPUT
9 CD CARRIER DETECT OUTPUT
5 0v INPUT
3.2 LED Indicators
Three LEDS on the front of the modem indicate the following states:
TX Green On when modem is transmitting data.
RX Green On when a RF carrier of greater than 0.9uV is detected by the modem.
This threshold can be adjusted by a potentiometer inside the modem.
POWER Red On when power is applied to the modem
4.0 OPERATION
A transmission is started by sending data to RD (pin 2) on the serial port. The radio modem
places this data in the transmitter buffer memory while it checks to see if the RF. channel is
free. If it is not then the data is stored in the buffer until the channel becomes free. If it is free
then a preamble message will be transmitted so that the receiving modems can align to the
incoming data.
The modem will then transmit a repeater command byte, if set, and a transmitter address
byte followed by the data that has been placed in the buffer memory. The transmission is
terminated when a gap of two data bytes is detected in the incoming data stream.
If more data is sent after a gap of two data bytes then the above sequence will be repeated.
When the receiving modem detects the presence of incoming data it takes CTS (pin 8) low.
The repeater command byte is decoded and the transmitter address compared to the
receiver address. If they are the same or if the global address of 00 is decoded or if the
address mode is switched off then the data will be presented at the serial output port TD (pin
3). At the end of the message CTS is taken high.
If the repeater command is decoded or the repeater mode set in the configuration menu then
the data will be stored and then re-transmitted.
The best results are obtained from the radio modem by setting the transmission speed to the
slow setting and the baud rate to either 4800 or 9600.
5.0 GETTING STARTED
5.1 Basic Connection
TRANSMIT (TD) ON HOST TO RECEIVE (RD) ON MODEM PIN 2
RECEIVE (RD) ON HOST TO TRANSMIT (TD) ON MODEM PIN 3
GROUND (0V) ON HOST TO 0V ON MODEM PIN 5

5.2 Power Connection
PIN 1 = POSITIVE 12V
PIN 5 = NEGATIVE 0V
5.3 Factory Setting
The radio modem is supplied with the following settings
Baud Rate 9600
Parity OFF
Repeater mode OFF
Error Correction OFF
Address Mode OFF
Transmitter Address 0 0
Receiver Address 0 0
Transmitter Test Mode OFF
Transmission speed SLOW (5K bits/sec)
RF Frequency (UK) 458.925MHz
RF Power 500mW
5.4 Plug and Play
Connect three wires to the RS232 serial port of the host terminal (0V, TD and RD) as
described above. Connect a regulated 12V, 1Amp power supply to the radio modem.
X7202 PC to Modem cables can be used along with a X7201 power supply.
Configure a PC in Microsoft Windows Terminal, Data Talk or any other terminal package
with the following settings:
9600 Baud
No Parity
1 Stop Bit
Local Echo
XON/XOFF to OFF
RTS/CTS to OFF (no handshaking)
Connect up a second modem in the same way.
Pressing a key on one PC will transmit the character to the other. Refer to the Section 8.0
Trouble Shooting if this does not happen.
If a second PC is not available simply power up the second modem. Configure the modem
connected to the PC in the repeater mode with the address mode switched off. This will
command the distant modem to repeat back the characters sent to it.
Fig 1 shows how an open network using the above configuration would work. All the data
transmitted from one modem will be received by all of the others. This is similar to an
RS485 network but instead of connecting the equipment by wire a radio modem is used.

FIGURE 1 OPEN NETWORK
6.0 CONFIGURATION
6.1 Configuration by Hard Wire Link
The modem can be configured by connecting a dumb terminal to the modem with following
settings:
9600 Baud
No Parity
1 Stop Bit
Local Echo
XON/XOFF to OFF
RTS/CTS to OFF (no handshaking)
Remove the power from the modem and connect 0v to pin 6 on the modem D Connector.
When the power is reconnected the following will appear on the screen:
WARWICK IND ELEC
X7200 MODEM *.*
BAUD PARY O/E REPT ERR DDR TXAD RXAD RFC TXON FX ?
B N O N N N OO OO Q N F Y/N
6.2 Configuration by Terminal Access
If the current configuration is known then the modem can be configured without the use of a
link between pin 6 and 0V.
Connect a dumb terminal to the D connector with the same baud rate and parity as that
already configured in the modem.
Switch the modem off and then on again.
Press the $ key and then the ESC key. The following will appear on the screen:
WARWICK IND ELEC
X7200 MODEM *.*

BAUD PARY O/E REPT ERR DDR TXAD RXAD RFC TXON FX ?
B N O N N N OO OO Q N F Y/N
To reconfigure the modem type N.
The pointer will then be placed under the baud rate setting.
6.3 Baud Rate Settings BAUD
A baud rate is entered by typing a letter A to E as follows
BAUD RATE LETTER
19200 A
9600 B
4800 C
2400 D
1200 E
The pointer then moves to the parity setting.
6.4 Parity On/Off parity
If a parity bit is required then type Y.
The parity bit is only used too and from the modem. It is not transmitted by the radio modem.
If over air parity is required then set the hosts at both ends to 7 bits plus a parity bit. This will
then transmit data plus parity over air.
6.5 Odd or Even Parity O/E
If parity is required either O for Odd or E for Even parity must be entered next. A letter must
be entered to proceed to the next setting.
6.6 Repeater Mode REPT
A modem can be set in two different repeater modes by typing Y.
6.6.1 Open Repeater (Echo Back Mode)
Any transmitting modem can command a receiving modem to repeat the data steam. This is
done by setting the Repeater Mode but not the Address Mode on the transmitting modem.
The repeater mode on the receiving modem does not have to be set.
Hence data can be automatically echoed back from any distant modem. This can be used to
test radio range and data integrity.

FIGURE 2 ECHO BACK MODE (OPEN REPEATER)
6.6.2 Chain Repeaters
If the Repeater Mode is used in conjunction with the Address Mode then a chain of modems
can be set up.
Each modem in the chain is given a receiving address and a transmitting address. The
transmitting address must be the same as the receiving address of the next modem in the
chain. The transmitting address and receiving address on each modem must be different.
MODEM 1 MODEM 2 MODEM 3 MODEM 4
REC ADD 22 33 22 33
TRANS ADD 33 22 33 22
The repeating modems can be used to send and receive data via their serial ports.
Alternatively they can be stand alone units just with power connected to them
FIGURE 3 REPEATER MODE
6.7 Error Correction Mode ERR
By selecting this option with a Y, a forward error correcting algorithm is brought into
operation. Redundant data bits are then inserted in the transmitted data.
If the receiving station also has the option selected, corrupt data will be detected and
corrected by means of the redundant bits. If the data is completely incoherent then the ASCII
character “CONTL E” (05h) will be loaded into the Rx serial port at the end of the message.

The algorithm has the effect of reducing the data transmission speed by one third but
extending the effective range.
6.8 Address Mode ADDR
Typing Y to this option will enable the Address Mode. The modem will transmit its TXAD at
the start of each data string. It will not pass receiver data to the serial port unless the
transmitter address of the incoming data string coincides with its receiver address RXAD.
The transmitter address 00 is used as a global address. Hence all radio modems in range
regardless of its receiver address will pass the data string to its serial port.
An “AT” (Attention) instruction can be sent from the host to change both the receiver address
RXAD and the transmitter address TXAD.
6.8.1 Basic Configuration
When the address option is selected, two modems with the following address will pass data
to their Hosts.
TXAD Modem 1 = RXAD Modem 2
RXAD Modem 1 = TXAD Modem 2
No other modems in the network will be able to communicate with them. This is useful for
high security data is transfer.
6.8.2 Station Addressing
The ATRnn and ATTnn instruction can be used to “dial up” distant modems as shown in fig 4.
The base station modern has its receiver address set to 01. The four distant stations, modem
2 to modem 5, have their transmitter address set to 01. Therefore any distant modem can
transmit data to the base station but not to each other.
The base station can dial up modem 2 by inserting the following instruction string at the start
of the data:
ATT02
In Hexadecimal code this will be:
A T T 0 2
41 54 54 30 32
Modem 3 can be dialled up in the same way with the instruction:
ATT03
The instruction string will not be transmitted over the air as long as it is sent to the modem
without any breaks.

FIGURE 4 STATION ADDRESSING
6.8.3 Global Addressing
The base station can send the same data to all the modems by using the Global Address 00
(Fig 5). The following instruction would be inserted before the data by the base station host:
ATT00
FIGURE 5 GLOBAL ADDRESSING

6.9 RF Channel RFC
One of the 17 RF channels can be set by typing a letter from A to Q as shown in Table
7.1.1. This frequency will be stored in the EEPROM and set every time the modem is
switched on.
This function can be disabled by typing $ instead of a letter A to Q. The modem will then
use the DIL switches to set the RF frequency. The initial response will be faster when power
is applied or when the stand-by mode (DTR) is used. In addition the RF channel can be
selected on site without the need for a terminal.
6.10 Transmitter Key TXON
Typing Y to this option will switch on the Transmitter. It will then act as a radio beacon so
that any of the following installation and test procedures can be carried out using a RF
power meter, the RX LED, the RSSI output or a scanning receiver.
6.10.1 RF Power Output
The power output of the transmitter can be adjusted using the RF power potentiometer and
a RF power meter connected to the antenna socket.
6.10.2 ERP and SWR
The Standing Wave Ratio (SWR) of an antenna, and the antenna feeder loses can be
measured using a RF Power Meter.
A maximum transmitter power (ERP) of 500mW is allowed for the UK, MPT1329 licence
except band. Some of this power is lost in the coaxial cable between the radio modem and
the antenna. It is possible to compensate for feeder losses by using a high gain, directional,
Yagi antenna. Care must be taken not to transmit more than 500mW therefore the RF
power must be reduced to compensate for the gain of the antenna minus the losses of the
antenna feeder. The RF power potentiometer can be set so that the ERP does not exceed
the legal limit.
6.10.3 Antenna Alignment
If directional yagi antenna are used it is important to aligned them correctly. This can be
done using a compass and ordinance survey maps. The alignment can be checked by
attaching a radio modem to the yagi antenna feeder, rotating the antenna and measuring
the peak signal strength using the RSSI output with a voltmeter connected to it. This will be
in the direction of the transmitter beacon.
6.10.4 Site Survey
A site can be surveyed for the best reception conditions using a scanning receiver set to the
same RF frequency or observing the RX LED on the radio modem.
A radio modem set in the TXON mode is placed at the base station site. A second radio
modem powered from a 12V battery can be moved around the site. If the RX LED remains
lit there is sufficient signal for good data reception. The RX LED will go out if the signal
becomes too weak.

6.11 Transmission Speed
Transmission speeds can be configured to either 5K Bits/sec or 10K Bits/Sec by typing F for
fast or S for slow. This speed is independent of the baud rate. It is recommended that the
baud rate and transmission speed should be as close to each other as possible.
F = 10K Bits/Sec
S = 5K Bits/Sec
A transmission rate of 5K bits/sec is recommended if maximum range is required.
7.0 RADIO TRANSMISSION
7.1 Radio Frequency
7.1.1DIL Switch Settings X7200HP
DIL RF Frequency RF Power
0 173.175MHZ 1W
1 173.150MHZ 1W
2 173.125MHZ 1W
3 173.100MHZ 1W
4 173.075MHZ 1W
5 173.050MHZ 1W
6 173.025MHZ 1W
7 173.000MHZ 1W
8 173.175MHZ 5W
9 173.150MHZ 5W
A 173.125MHZ 5W
B 173.100MHZ 5W
C 173.075MHZ 5W
D 173.050MHZ 5W
E 173.025MHZ 5W
F 173.000MHZ 5W
7.3 Radio Propagation
When installing a X7200 Radio Modem there are a number of factors that should be
considered as they will affect the performance of the radio link. These are:
Transmitter power output.
Sensitivity of the receiver.
Height of transmitter and receiver antenna.
Length and type of the coaxial feeder cables to the antenna. These should be low loss
RU67 type and kept as short as possible. As a rule of thumb the RF power is halved
every 10m of antenna feeder. It is better to keep the signal wire long and the antenna
feeder short.
Type of Antenna used.
Surrounding Topography.
Interference for other networks operating on the same frequency.
The Weather.

7.4 Antennas
The main types of antenna used in telemetry applications are as follows:
Helical
End Fed Dipole
Yagi
7.4.1 Helical Antenna
The helical stub antenna is robust, low cost and physically small. It has a gain less than unity.
Range of up to 2Km.
7.4.2 End Fed Dipole
The end fed dipole antenna has a unity gain. Its main application is to provide cost effective
omni-directional radiation.
Range 10 to 20 Km
7.4.3 Yagi
This antenna has a high gain typically twice (3dB) to ten times (10dB) the input power in the
direction of orientation. It is the type of aerial commonly used in domestic televisions.
The output power of a transmitter connected to a Yagi antenna has to be reduced to conform
to the DTI specification. This has the advantage of reducing the overall power consumed by
the transmitter without effecting the range in the direction of orientation. It also reduces
interference from other users.
The receiver signal is also amplified if a Yagi antenna is used thereby extended range in the
direction of orientation to around 20 Km line of sight.
8.0 TROUBLE SHOOTING
8.1 No Data Transmission
Check that TD and RD are connected to the 9 way D Connector correctly. This can be
checked by using a voltmeter:
a) Connect the Host to the Modem.
b) With no signal present, measure the voltage between:
0V (Pin 5) and TD (Pin 3)
0V (Pin 5) and RD (Pin 2)
c) Both should be between -5V to -15V.
If only one is at a negative voltage then the RD and TD connections are reversed.
8.2 No Data Reception
If the RX LED on the receiver is not lighting at the same time as the TX LED on the
transmitter then check the RF frequency DIL switches on both modems to see if they are set
to the same RF frequency.

If the RX LED is lit when no data is being transmitted then there might be another user on the
channel. Select an RF channel on the DIL switches were the RX LED is not lit. Remember to
switch the power off and then on again when you make a change in the DIL switch settings to
load the new value.
If RX LED is flickering on all RF channels then look for a source of local interference such as
a switch mode power supply or a computer in close proximity.
If there are other radio modems or radio telemetry systems operating on adjacent frequencies
on the same site then the antenna on your system must be mounted at least 3m away from
the antenna of the other systems. This will prevent the transmitter of one system interfering
with the receiver of the other.
8.3 Corrupted Data
Corrupted data can be caused by poor power supplies.
Check that the power supply is regulated at 12V and has a ripple of less than 50mV on load.
It must also be capable of delivering an inrush current of 0.7Amps for 20mSec. when the
radio modem starts its transmit cycle.
The ripple voltage can be measured with a voltmeter set on A.C. volts.
8.4 Radio Path
The radio path can be tested by configuring the transmitting modem to the Repeater Mode.
Exit the configuration menu and transmit a character from the dumb terminal
This will be echoed back from the distant modem if there is a good transmission path.
8.5 HELP LINE NUMBER 01455 233616
9.0 WARNING
Warwick Wireless Limited reserve the right to change the design or specification of the X7200
Radio Modem without notification. In addition Warwick Wireless Limited take no responsibility
for the installation and operation of the radio modem.
All documentation and software are copyright.
Doc: X72E Version 3.0