Satel SATELLINE-1AS User manual

SATELLINE-1AS and SATELLINE-2AS
Radio Data Modem
USER GUIDE

TABLE OF CONTENTS Page
1 SATELLINE-1AS and SATELLINE-2AS radio data modems 3
1.1 Radio data modem 3
1.2 RS-232 Pin Connections 4
1.3 Technical Specifications 6
2 Asynchronous Data Transmission 8
2.1 Asynchronous character 8
2.2 Effects of character length on transmission 9
2.3 Data speeds 9
2.4 Transmission 9
2.5 Reception 10
2.6 Delays during data transmission 10
3 Multi Modem Data Systems 10
3.1 Required sequence of data characters 10
3.2 Polling 10
3.3 Multi Master 11
4 Planning a Radio Modem Network 11
4.1 Factors affecting quality and distance of the radio connection 11
4.2 Radio field strength 12
5 Installation 13
5.1 RS-232 Interface 14
5.2 Supply of current 14
5.3 Mounting the antenna 15
6 Equipment 18
6.1 The connection of antennas to radio modems 18
6.1.1 Hand portable equipment 18
6.1.2 Equipment installed in vehicles 18
6.1.3 Base station 18
6.2 Cables 19
6.2.1 RF cables 19
6.2.2 Interface cables 19
7 Check List 20
Appendices
1. The timing diagram of RS-232 interface of SATELLINE-1AS and SATELLINE-2AS
radio modems
2. Selecting of radio channel of SATELLINE-2AS
3. Table of selectable radio channels
4. SATELLINE-1AS/2AS RSSI curve
**** Due to continuous product development SATEL OY reserves the right to
change specifications without notice ****
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1SATELLINE-1AS and SATELLINE-2AS Radio Data Modems
This user guide is meant for SATELLINE-1AS, SATELLINE-1ASm2, SATELLINE-2AS and
SATELLINE-2ASm2 radio modems. Since their electrical function is identical and only their
housing is different, the brand names SATELLINE-1AS and SATELLINE-2AS refer to every
model mentioned above.
1.1 Radio Data Modem
MODEM
RECEIVER
TRANSMITTER
RS-232
ANALOG
13
11
6
7
9
2
3
4
5
15
1
8
TD
RTS
CTS
SGND
RD
CD
LED
ON
RSSI
+VB
DTR
GND
Fig. 1. SATELLINE-1AS radio modem
The SATELLINE-1AS radio data modem is comprised of a 450 MHz transmitter, receiver
and a modem board, housed in a compact resistant aluminium casing. It has an RS-232
interface that allows easy connection to a variety of data networks.
The SATELLINE-1ASl radio data modem has a maximum data speed of 1200 bps. It is
especially suitable for longer distances because of its better sensitivity.
The SATELLINE-2AS differs from SATELLINE-1AS by the radio part. Both the transmitter
and the receiver parts are on the same board (transceiver) and their function is based on
the synthesized radio technique. The frequency stability is better and it is possible to change
the radio channel.
The data transmission formed by radio modems resembles a cable. Unlike in cables the
data transmission is half-duplex. The delays in transmission due to the half-duplex
transmission and possible interferences must be considered when planning a system.
Should Simplex operation be required, it can be achieved by installing a SATELLINE-1T
transmitting modem and a SATELLINE-1R receiving modem.
Typical applications of radio modems are :
wReplacing a cable in situations where installation of such a cable is difficult, expensive
or even impossible.
wData transmissions between mobile or portable terminals
wWireless alarm transmission
wTelemetry
wRemote control
SATELLINE-1AS and SATELLINE-2AS
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wTransferring text to displays
wFor use with Global Positioning System (GPS)
With two SATELLINE-1AS/-2AS radio data modems it is easy to make up point to point
connections. The power level of the transmitter is 0,5 W. It is possible to reach distances
from 2 to 30 km depending on topographical conditions and antenna locations. On
special request it is possible to manfacture transmitters with the maximum output power of
1,0 W. Country specific laws of radio communication must always be followed.
The radio data modem operates well in data networks where the same channel is used by
several mobile terminals. In such systems the protocol can be either polling mode, in which
the data communication is controlled through one of the radio modems or multimaster
mode, in which any one of the radio modems can initiate the data transmission when the
radio channel is free.
When the radio data modem is in the receiving mode, a data squelch facility is
incorporated into the modem board to effectively ignore reception of error characters to
the RD line which may have been caused by radio interference.
1.2 RS232 Pin Connections
Supply Voltage positive pole-VB15
14
Request
to
Send
IN
RTS
13
-
-
-
12
Transmit DataINTD11
Data
Set
Ready
OUT
DSR
10
Receive
Data
OUT
RD
9
Ground-GND8 Signal Ground-SGND7
Clear
to
send
OUT
CTS
6
Receiving
signal
strength
indicator
OUT
RSSI
5
LED on switching-LED ON4
LED
on
switching
-
LED
ON
3
Carrier
Detect
OUT
CD
2
Data Terminal ReadyINDTR1 OperationSD *)LineD-connector Pin
SD = Signal direction from radio data modem
IN = Input OUT= Output
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Operation description of the lines pin by pin:
1 DTR operates as an ON/OFF switch of the modem "0" (0 V...-12 V)
"1" (+5 V...+12V)
2 CD indicates a signal on the radio channel exceeding the level of sensitivity of
the modem (it can record radio interferece signal).
3 and 4 Will be connected together in models with LEDs, where the most important
lines are indicated by leds.
5 RSSI measures the received signal strength of the field of the transmitting radio
(starts approximately from 0.5 V and goes up to 5 V ). The strength of the field
increases with the voltage. See appendix 4
6 CTS indicates when the radio data modem is clear to receive data via the
RS-interface
7 SGND is the signal ground
8 GND is the ground of supplying voltage
9 RD received data
11 TD input of transmitted data
13 RTS gives radio modem a request to send, starts the transmitter (answer by CTS
line)
15 Supply voltage
The RSSI (Received Signal Strength Indicator) is available on the radio data modem. This
feature indicates the level of field strength of an incoming transmission and is particularly
useful in systems that have several receivers as it is possible to select the receiving device
that has the optimum incoming signal.
The radio modem also incorporates a CD (Carrier Detect) line output which is activated
5...10 ms after the activation of the RTS line of the transmitting modem. The CD line also
indicates the presence of either a signal on the radio channel or an interference signal
above the sensitivity limit of the radio modem.
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1.3 Technical Specifications
SATELLINE-1AS
Satelline-1AS complies with the following international standards:
CEPT T/R 20-04 (radio standard) and the model m2 also with prETS 300 683 (EMC
standard)
TRANSMITTER
Frequency Range 400...470 MHz
Channel Separation 25 kHz
Frequency Stability < ± 2.5 kHz (± 5 ppm)
No. of Channels 1 (Crystal)
Carrier Power 400 mW/ 50 ohm (+ 26 dBm)
Carrier Power Stability - 2 dB / + 1 dB
Frequency Deviation ± 2.5 kHz...± 3.0 kHz
Adjacent Channel Power < 200 nW
Spurious Radiations < 250 nW
Method of Modulation FSK
RECEIVER
Frequency Range 400...470 MHz
Channel Separation 25 kHz
Frequency Stability < ± 2.5 kHz (± 5 ppm)
No. of Channels 1 (Crystal)
Maximum usable sensitivity BER < 10 E-4 1AS 1ASl
300 bit/s -114 dBm -116 dBm
600 bit/s -114 dBm -116 dBm
1200 bit/s -112 dBm -116 dBm
2400 bit/s -110 dBm
4800 bit/s -110 dBm
Co-Channel Rejection > -8 dB
Adjacent Channel Selectiv. > 60 dB
Intermodulation attenuation > 60 dB
Spurious radiations < 2 nW
MODEM
Interface RS-232
Interface Connector D15 connector, female
Data Speed 300 - 4800 bit/s (1AS), 300 - 1200 bit/s (1ASl)
Modulating Signal Manchester-coded NRZ
Data Formats Asynchronous data
character length 10 or 11 bits
Data Squelch On the modem board: prevents interference from
appearing to the RD line in receiving mode
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GENERAL
Operating Voltage + 10...+ 13 Vdc
Current Consumption When DTR is "0": 0.4 mA
When DTR is "1": Receiving: 55 mA
Transmitting: 330 mA
Antenna Connector TNC, 50 ohm, female
Size H x W x D 137 x 67 x 29 mm
Installation plate 130 x 63 x 1 mm
Weight 230 g
Temperature Range - 25 C...+ 55 C
SATELLINE-2AS
Satelline-2AS complies with the following international standards:
I-ETS 300 220, CEPT T/R 20-04 (radio standard) and the model m2 also with prETS 300
683 (EMC standard)
TRANSCEIVER
Frequency Range 400...470 MHz / base band 2 MHz
Channel Spacing 25 kHz
Number of Channels 16 (selectable by a Hex switch)
Frequency Stability < ± 1.5 kHz
Method of Modulation FSK
Transmitter
Carrier Power 500 mW/ 50 ohm ( + 27 dBm)
Adjustment range 20mW... 1 W / 50 ohm (factory set)
Carrier Power Stability + 1 dB / - 2 dB
Frequency Deviation ± 2.5 kHz
Adjacent Channel Power < 200 nW
Spurious Radiations I-ETSI 300 220
Receiver
Sensitivity < -108 dBm (BER < 10 E-4)
Co-channel rejection > 8 dB
Adjacent channel selectivity > 65 dB
Intermodulation attenuation > 65 dB
Spurious radiations < 2 nW
MODEM
Interface RS-232
Interface Connector D15 connector, female
Data Speed 300 - 4800 bit/s
Modulating Signal Manchester-coded NRZ
Data Formats Asynchronous data: 10 or 11 bits
Data Squelch On the modem board: prevents interference
from appearing to the RD line in receiving
mode
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GENERAL
Operating Voltage + 10...+ 14 Vdc
Current Consumption When DTR is "0": 2,8 mA
When DTR is "1": Receiving: 90 mA
Transmitting: 600 mA
Antenna Connector TNC, 50 ohm,female
Size H x W x D 137 x 67 x 29 mm
Installation plate 130 x 63 x 1 mm
Weight 250 g
Temperature Range - 25 °C...+ 55 °C
Labelling information:
Ser.no. 96052938 Freq. Ch F 468.200 MHz
SATEL OY
Tel: [phone], Fax: [phone]
wSerial number (year+ week + manufacture number)
wFrequency, set by the manufacturer. F = position of the channel switch and the
frequency corresponding 468.200 MHz
wManufacturer's contact information
2Asynchronous Data Transmission
2.1 Asynchronous Characters
Data characters can be transmitted either in 10 or 11 bits and either in 8 or 9 bit data
characters between the start and stop bits respectively. These options are factory set. Thus,
they have to be decided in advance.
Characters are formatted in accordance with the ANSI standard asynchronous characters.
See diagram below.
7 D
S
S
S
S
8 D
8 D
9 D
PL
L
L
L
P
10 bit
11 bit
S = start bit
P = parity bit
L = stop bit
D = data bit
Data transmission between the radio data modems is synchronous. The radio data modem
corrects the time difference between a clock signal from the data transmitting equipment
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(DTE) and its own clock signal by adding one stop bit if required. The radio data modem
transfers parity bits as they are received.
2.2 Effects of character lenght on transmission
The transmitted data character can be either 10 or 11 bits, the length of these characters is
determined by hard wiring on the modem board.
It is important that the transmission from the data terminal equipment to the radio data
modem matches the selected character length. In the event of a mismatch transmission
errors will be shown at the receiving end as "error characters" and the data transmission will
be discontinued.
NOTE! The length of the character from the data terminal equipment must
correspond to that of the modem.
2.3 Data Speed
The data speed of the radio modem can be 300, 600, 1200, 2400 or 4800 bits/s. The
data speed is carried out by changes on the modem card.
2.4 Transmission
There are two different methods of initiating data transmission.
1 RTS/CTS handshaking
2 Data connected directly to TD line
The first method using RTS/CTS handshaking has to be used for data speeds of 2400 and
4800 bit/s. This method is initiated from the radio data modem requesting permission to
send. This is achieved by switching the RTS line from an OFF to an ON state. The
subsequent reception of data will cause the CTS line to be raised and the data transmission
will be sent on the TD line. If there is an active radio transmitter on the system with the same
radio channel the CTS line will not be raised.
The second method of transmission operates within the range of 300 to 1200 bit/s. In this
case the transmitter is switched directly to the TD line.
Should a break in transmission occur e.g. caused by a weak radio field, transmission can
only be restarted by switching off the transmission for a period of at least 20 ms before
re-sending.
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2.5 Reception
The radio modem is ready to receive data when the supply voltage is switched on and the
DTR line is in the "ON" state.
Equipment connected to the radio data modem receives information about the incoming
data by detecting the change in state of the RD line. In addition, the change in state of the
CD line also allows the equipment to detect the start of a transmission.
2.6 Delays during data transmission
Delays may occur when transmitting or receiving data using the radio data modem.
These delays are:
Wake-up time DTR OFF/ON 30 ms (1AS) / 400 ms (2AS)
RTS/CTS delay 8...10 ms
Rx/Tx turn round delay 2 x 40 DBP + 20...25 m (40ms @4800 bit/s)
(50ms @2400 bit/s)
Rx ON connecting time 10 ms
Synchronization sequence 10 DBP (DBP=Data Bit Period) (e.g. 2ms @ 4800 bit/s)
3Multi Modem Data Systems
3.1 Required sequence of data characters
The data should be transferred in continuous sequences or in sequences divided into
blocks. Sequences that are too short (e.g. 1 character) should not be sent because
"overhead-information" (synchronization plus terminal address) takes a great deal of
processing time and thus slows down the data transmission. The recommended length of a
data packet is 50 - 500 characters.
The size of a system using one radio channel can be increased when the timeframe of
transmission of one terminal is short. This must be taken into account when planning the
system. The operating range of the system can be extended by increasing both the number
of base stations and the number of radio channels.
It is important that only one transmitter can be active on the same channel at the same
time.
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