 |
|
RPM3
|
| The UHF Radio Packet Modem (RPM3) is
a low cost intelligent radio packet modem that enables a two
way radio network/link to be simply implemented between a number
of digital devices. The RPM3 uses addressable data packets with
error checking, packet acknowledgements and retransmissions
to achieve a reliable transparent wireless data link. Built
for ease of use and rapid installation, the serial interface
ensures direct connection to microprocessors or to RS232 port
via RS232 driver while remote configuration enables post installation
setup of the modem. |
|
Figure 1: RPM3-914-17 |
|
|
|
|
|
Features
- Addressable point-to-point
mode
- Point-to-Multipoint and broadcast modes
- Inverted RS232 interface at 5V or 3V CMOS level
- DTE speed 600-115200bps
- Overall throughput:
17kbps with ACK and
28kbps wothout
ACK
- Single 5V or 3V supply
- 15mA during data streaming at maximum rate
- Flow control - Hardware
(CTS), none
- Available in 869.85MHz (EU), 914.50MHz (North America)
- Usable range up to 200m (650ft.)
- No Duty Cycle Restriction
- Built-in command line
configuration
- Built-in RF link diagnostics
- Remote over-air unit
configuration
- Low operating current,
Auto standby mode
- Conforms to European
ETSI EN 300 220-3 and EN 301 489-3
- FCC approved (under part 15.249) - click
here for Grant of Equipment Authorisation
- Dimensions - 39 X 23 X 10 mm
|
|
|
Applications
- Telemetry and telecontrol
- EPOS equipment, barcode scanners,
belt clip printers, stock control, job allocation
- Remote data acquisition system, data
loggers
- In-building environmental monitoring
and control system
- High-end security and alarm signalling
- Automated Monitoring and Control Systems
- Fleet management, vehicle data acquisition
|
| Evaluation Platform: SPM2/RPM
Evaluation Kit |
| |
 |
| |
INTRODUCTION
The RPM3 is a self-contained radio modem
module that requires only a simple antenna, 5V supply and
a serial I/O port on a host microcontroller or PC.
The module provides all the RF circuits
and processor intensive low level packet formatting and
packet recovery functions required to inter-connect any
number of devices with serial port in a radio network.
A continuous stream of serial
data downloaded by a Host microcontroller into the RPM3
serial receive buffer is transmitted by the RPM3's transceiver
and will "appear" in the serial buffer of the
addressed RPM3 within radio range.
Figure 2: Point to point wireless
link with RPM3 + Host microcontroller
|
|
| |
| 1. FUNCTIONAL DESCRIPTION |
|
The RPM3 is a connection oriented modem
module for sending and receiving serial data via an RF communications
link.
The RPM3 handles all necessary protocol
related functions of validation and retries to ensure error
free and uninterrupted data is sent over the communications
link. All data transfers between a pair of RPM3s are fully
acknowledged, thus preventing the loss of data. Bit coding
and checksums are used on the data packets to ensure the validity
of the received data at the remote end.
|
Figure 3: RPM3 block diagram |
| |
|
1.1 OPERATING STATES
The RPM3 has three normal operating states:
· SHUTDOWN
· STANDBY
· CONNECTED
SHUTDOWN
The SHUTDOWN state is entered by asserting the WAKE/DTR
input pin high (Vcc). It effectively forces the RPM3 into
a suspended state. No communications can be made with the
RPM3 in this state. WAKE/DTR
pin should be pulled Low by host or connected to 0V to Enable
the RPM3.
STANDBY
Immediately after power up and during normal operation, the
RPM3 will automatically enter standby mode where it is waiting
for a connection request from a remote RPM3 module.
While in this mode a remote connection request can be received
which will place the RPM3 into a connected state allowing
it to then start receiving data from the remote unit. The
connected host device can also send data to the RPM3 via the
serial interface which will force the module to send a connection
request to the remote RPM3 module, thus effectively setting
up a logical connection between two units and allowing data
to be transferred.
CONNECTED
On receipt of a connection request from a remote unit, the
RPM3 immediately enters a connected state. This effectively
allows the RPM3 modems to start sending and receiving data.
In-coming data is sent to the host via the serial port in
the same form as it was given to the remote RPM3 module.
|
|
| |
Figure 4: RPM3 transmitting data at
28kbps during ZMODEM file transfer to a remote RPM3 |
| |
|
2. THE HOST INTERFACE
|
| 2.1
SIGNALS
The connection to the RPM is a full duplex serial interface
supporting baud rates from 600bps to 115200bps. Additional
control signals are provided to assist in flow control, configuration
and power saving in the RPM3.
|
| |
 Figure 3: Physical
dimensions and pinouts |
| |
|
Pin name
|
Pin
|
Pin function
|
Input /Output
|
Description |
| RF GND |
1, 3 |
RF signal ground |
- |
BNC casing/coax braid
connection |
| RF |
2 |
RF signal |
In/Out |
Antenna pin/coax
core connection |
| RF SELECT |
4 |
Receiver Select |
In/Out |
Internal RF Receiver Enable
to BiM3A or RF Receiver Active Indicator |
| TX SELECT |
5 |
Transmitter Select |
In/Out |
Internal RF Transmitter
Enable to BiM3A or RF Transmitter Active Indicator |
| TXD/AF |
7 |
Transmitted Data or demodulated
signal |
In/Out |
Transmitted Packetised
Data to BiM3A
Analogue Demodulated signal from BiM3A |
| D3 |
8 |
FRPC Data line |
NC |
Internal data line between
RPM and FRPC |
| D2 |
9 |
FRPC Data
line |
NC |
Internal data
line between RPM and FRPC |
| SIGNAL |
10 |
Preamble Detect |
Out |
Valid preamble indicator |
| RST |
11 |
FRPC reset |
NC |
Resets FRPC
which also isolates BiM3A |
| RXA |
12 |
Receive Acknowledge |
NC |
RPM to FRPC download request
acknowledge |
| RXR |
13 |
Receive Request |
Out |
Valid Data packet indicator |
| RESET |
14 |
Reset |
In |
Hardware reset of the
RPM3 |
| SETUP |
15 |
Enter Setup |
In |
Enter RPM3 configurator
after a RESET |
| WAKE/DTR |
16 |
Wake or Shutdown |
In |
Wakes RPM3 when low, shuts
down when high |
| TXD |
17 |
Serial transmitted data |
In |
Host (DTE) to RPM3 serial
transmit data |
| RXD |
18 |
Serial Received data |
Out |
RPM3 to host (DTE) serial
received data |
| CTS |
19 |
Clear to Send |
Out |
Hardware flow control
of data from host (DTE) |
| DEFAULT |
20 |
Force 9600bps |
In |
Force the RPM3 serial
interface to 9600bps |
| Vcc |
21 |
Vcc Supply |
In |
+5VDC or +3VDC regulated
supply |
| GND |
6, 22 |
Ground |
- |
Supply Ground internally
connected to RF GND |
| |
|
| Notes: |
1. RXD/TXD lines are true
data |
| |
2. Active low SETUP, DEFAULT
inputs require external 10kW pullup
to VCC |
| |
3. Logic levels are 5V
CMOS unless 3V variant is used |
| |
4. WAKE pin
should be pulled to ground if DTE cannot provide DTR signal |
| |
5. TXSELECT,
RXSELECT, SIGNAL, RXR, CTS can be connected to LEDs via
1kW series resistors |
|
|
| |
| 2.2
RADIO PACKET MODEM RESET
RESET
The Reset signal is internally pulled up to Vcc via a 10kW
resistor. A reset aborts any transfers in progress and restarts
the RPM3.
HOST DRIVEN RESET
Minimum low time: 1.0 ms, after
reset is released (returned high). The host should allow a
delay of 1ms after reset for the RPM3 to initialise itself.
|
| |
| 2.3
HOST TO RADIO PACKET MODEM DATA TRANSFER
Data is transferred between the RPM3 and the HOST using an
asynchronous serial protocol. The default protocol settings
are 8 data bits, no parity and 1 stop bit (8n1). The baud
rate setting for the serial interface is user settable from
600bps to 115200bps.
TXD
Data from the connected host is received by the RPM3 through
TXD pin.
CTS
A single handshake line, CTS, controls the flow of data into
the RPM3. The serial receive buffer of the RPM3 is 96 bytes
deep. The CTS will be asserted high (Vcc) by the RPM3 when
the receive buffer hits approximately 66% full. It is advisable
to limit the number of characters sent to the RPM3 after the
CST control line is asserted. This will help to reduce the
possibility of lost data due to internal buffer overruns in
the RPM3. The RPM3 will clear the CTS when the internal serial
receive buffer falls below 33% full.
RXD
Upon the RPM3 receiving data from a remote unit, the received
data is sent to the connected host device through the RXD
pin.
2.4 ENTERING RADIO PACKET MODEM CONFIGURATOR
Configuring the RPM3 is accomplished by using a built-in
command line configurator. The configurator is entered by
asserting the SETUP input of the RPM3 while resetting the
RPM3.
SETUP
Holding SETUP low during a reset cycle will force the modem
into the configurator. The state of this input is checked
while the RPM3 starts up from either power on or reset.
HOST DRIVEN SETUP
The Setup pin may either be driven by the host (recommended)
to enable host controlled configuration of the RPM3 or pulled
up to VCC via a suitable pull-up resistor (10kW).
2.5 FORCING DEFAULT SERIAL BAUD RATE
Asserting this pin low forces the RPM3 to startup with a
default baud rate of 9600bps, 8 data, one stop and no parity.
DEFAULT
During a RESET the HOST must hold DEFAULT low to force the
RPM3 serial interface to default to 9600bps. This is ideal
if the serial baud rate has been forgotten or incorrectly
set.
HOST DRIVEN DEFAULT
The DEFAULT pin may either be driven by the host (recommended)
or pulled up to VCC via a suitable pull-up resistor (10kW).
2.6 FORCING RADIO PACKET MODEM INTO SLEEP
MODE
Asserting the WAKE input high forces the modem into a low
power sleep mode. This effectively shuts down the RPM3 and
prevents it from sending or receiving any data. It is a method
for conserving power when the modem is not required.
WAKE/DTR
During normal operation WAKE pin can be pulled high to force
the RPM3 to shutdown into low power sleep mode.
HOST DRIVEN WAKE
The WAKE pin may either be driven by the host (recommended)
or pulled low to 0V.
|
|
| |
| TECHNICAL SPECIFICATIONS
|
| General |
|
| Operating Voltage |
5VDC or 3VDC |
| Operating Current |
|
| ACKMODDE
ON |
|
| Transmitting |
Average 15mA
(Data streaming) |
| Receiving |
Average 15mA
(Data streaming) |
| ACKMODDE
ON (10mW) |
|
| Transmitting |
Average 14mA
(Data streaming) |
| Receiving |
Average 15mA
(Data streaming) |
| Auto
standby |
4mA (Waiting
for Connection) |
| Power
down |
70mA |
| |
|
| Standard
operating frequency |
869.85MHz (EU)
914.50MHz (USA, Canada) |
| TX spectral bandwidth
@ -40dBc |
250kHz |
| |
|
| Operating Temperature
|
-20ºC to +70ºC |
| Configuring options |
Built-in command line
configurator |
| |
|
| Interface |
|
| Serial Interface |
Inverted RS232 at 5V or
3 CMOS level |
| Serial Protocol |
8 data/1 stop/no parity |
| Serial Signals |
RXD, TXD, CTS, WAKE |
| Power down Control |
Via WAKE/DTR signal |
| Serial Handshaking |
Selectable as CTS signal
or none |
| DTE Interface
Speed |
600/1200/2400/4800/9600/19200/38400/57600/115200 |
| Air Interface Speed |
64kbps |
Overall throughput
|
|
|
Acknowledged
|
17kbps (max); 3.6kbps
(slots); 1.8kbps (slotsw) |
|
Unacknowledged |
28kbps (max); 3.6kbps
(slots); 1.8kbps (slotsw) |
| |
|
| Receiver |
|
| Sensitivity |
-100 dBm
for 1ppm BER |
| LO leakage
(conducted) |
-110dBm (max)
|
| |
|
| Transmitter |
|
| Output Power
(typical) |
+2dBm (Eu version)
-1dBm (US version) |
| Spurious Emissions |
-40dBm |
|
| NOTES: |
1. RPM3 uses BiM3A (64kbps UHF Wide Band FM) transceiver
for its RF interface. Please refer to BiM3A data sheet for
further details on the RF specification.
2. BiM3A consumes 7mA on transmit and 11mA on receive
|
|
| |
| 3.0 RADIO
PACKET MODEM CONFIGURATION
3.1 ENTERING THE CONFIGURATOR
The RPM3 is configured by entering the built-in software
configurator. Current argument can be displayed by entering
parameter / command without argument
|
| |
| 3.2 USER CONFIGURABLE PARAMETERS |
| CONFIG |
Display a list of the current
RPM3 configuration.
This wil also set FLOW control to none
to enable simple 3 wire communication
|
| Valid range |
None |
| DEFAULT |
Set all RPM3 configuration
settings to their factory default values. |
| Valid range |
None |
| RESET |
Exit
the modem and force a software reset.
Any changed parameters will take effect after the modem
has restarted.
When exiting the configurator, the HOST device must ensure
the SETUP pin is high otherwise the configurator will
be re-entered after the reset. |
| Valid range |
None |
| UNIT |
Sets
the unit number.
Two RPM3 modules can communicate with each other provided
they have matching Unit numbers and Site codes. |
| default |
0 |
| Valid range |
0 to 15 |
| SITE |
Sets
the Site address.
The site number is used to distinguish between groups
of operating modems. The site code is an address extension
to the unit number. |
| default |
0 |
| valid range |
0 to 7 |
| ADDR |
Updates
the unit number value.
This command is used for changing the unit number in RAM
without updating the unit number stored in EEPROM. This
enables the RPM3 to support point-to-multipoint communications.
Upon using this command the configurator is exited and
the modem operation is resumed. The modem is not reset
when the configurator is exited. |
| Valid range |
0 to15 |
| BAUD |
Sets
the host interface baud rate.
The changed baud rate will take effect after resetting
the RPM3. |
| default |
9600 |
| valid range |
600, 1200, 2400, 4800,
9600, 19200, 38400, 57600, 115200 |
| THRUPUT |
Sets
the on-air data throughput.
Three possible settings are provided.
Max: sets the maximum data
throughput of the RPM3.
Slots: effectively reduces
the on-air throughput. This opens up 'time slots' allowing
other RPM3 pairs, operating within close proximity, equal
opportunity to transmit data.
Slotsw: increases the 'time
slots' even further to allow more RPM3 pairs to operate. |
| default |
max |
| valid range |
max, slots, slotsw |
| FLOW |
Sets
the serial flow control between the host and RPM3.
Using no flow control enables the RPM3 to be used with
a 3 wire serial link (TXD, RXD, GND). Care must be taken
in order to prevent overflowing the 96 byte serial receive
buffer in the RPM3.
Using hardware flow control enables the RPM3 to control
the flow of serial data being received. |
| default |
hw
|
| valid range |
hw, none |
| SERDLY |
Sets
the serial data receive to packet transmit delay.
When the RPM3 receives the first byte of data from the
host, it starts a timer running. Either a full buffer
of data to send or a timeout of this timer will allow
the packet to be transmitted.
Fine tuning this delay for the baud rate the RPM3 is operating
at can significantly increase throughput while reducing
unnecessary transmissions. |
| default |
2 (x10ms) |
| valid range |
2 to 255 (x10ms) |
| SHDN |
Sets
the action of the WAKE input.
Setting SHDN to ON will cause the RPM3 to monitor the
WAKE input. When WAKE is taken high the RPM3 will be forced
into low power sleep mode, thus reducing current consumption.
Subsequently lowering the WAKE input will bring the RPM3
out of low power sleep mode.
SHDN should be set to OFF or WAKE pin should be pulled
Low when the host (DTE) cannot provide DTR control signal
to wake RPM3 in a 3-wire serial interface. |
| default |
on |
| valid range |
on, off |
| RETRY |
Sets
the number of data retry attempts.
RF interference can cause a transmitted data packet to
be lost or corrupt on reception. If this happens the RPM3
will retransmit any unacknowledged transfer. The transmission
will be retried the specified number of times before the
link to the remote unit is considered 'lost' and the data
purged. |
| default |
5 |
| valid range |
1 to 63 |
| STRTMSG |
Enables
the startup message.
The startup message is enabled by default, thus giving
an immediate indication of the operation of the RPM3.
The message can be disabled prior to deployment of the
RPM3 module. |
| default |
On |
| valid range |
on, off |
| ACKMODE |
Enables transfer acknowledgements.
This function enables packet transfer acknowledgements
to be returned for every outgoing packet. Packet acknowledgements
aid in the delivery of error free and consistent data
transfers between a pair of modems. Disabling the acknowledgements
results in higher data throughput between modems, but
does not protect against lost data due to RF interference.
It should be disabled while using RPM3 in a broadcast
mode.
|
| default |
On |
| valid range |
on, off |
| REMOTE |
Enables
remote configuration.
Over-air remote configuration of a RPM3 module is possible
once it has been enabled. The remote command is used to
send remote configuration commands. See the following
chapter for a overview of remotely configuring a RPM3
module. |
| default |
Off |
| valid range |
on, off |
| RADAR |
Starts the radar test.
Used as a range or confidence test between RPM3 modules
within the same site.
|
| parameter |
Unit number between 0
and 15. |
|
|
| |
| To configure the
RPM3 the HyperTerminal should be set with the following settings. |
Figure 6: Serial Port settings to
use RPM3 Configurator |
| Hardware flow control should
be disabled. Default baud rate of the RPM3 is 9600bps. However
if the default baud rate of the RPM3 is changed then the baud
rate of the HyperTerminal should be matched or DEFAULT pin should
be pulled Low force the RPM3 baud rate to 9600bps. |
|
|
Figure 7: RPM3 configuration using
HyperTerminal |
| User configurable
parameters described in section 3.2 should be entered in the
command prompt > followed by Carriage Return (CR) key. Then
SETUP should be pulled-up to VCC and RPM3 should be RESET to
exit the configurator and for the new parameters to be used
by RPM3. |
|
| |
|
4.0 EXTENDED RADIO
PACKET MODEM FEATURES
4.1 THROUGHPUT
The RPM3 supports three rates, max (17kbps), slots (3.6kbps)
and slotsw (1.8kbps), of over-air throughput
MAX: When set to maximum and
streaming data at the RPM3, the data is sent as quick as possible.
For host baud rates of 9600bps and above, data is transmitted
continuously with minimal delay between sequential packets.
When this occurs, there is effectively no airtime for another
pair, operating in close proximity, to transmit without causing
collisions. The maximum over-air throughput that can be achieved
is 17kbps with ACK and 28kbps without ACK.
|
Figure 8: RPM3 pair streaming data
without gap for another RPM3 pair |
| In Figure
8, RS232 serial data bytes accumulated in the receive buffer
is transmitted as two 10kbps bursts by transmitting RPM3 with
gaps just enough to receive ACK from receiving RPM3. |
| |
Figure 9: RPM3 pair streaming9600bps
serial data with ACK at maximum throughput |
| For continuous
data transmission at baud rates above 2400bps (with ACK) or
4800bps (without ACK), hardware flow control should be used
to prevent the host from causing receive buffer overrun errors.
RPM3 will signal CTS pin to stop/allow the host depending on
its Receiver Buffer level. |
|
| |
| SLOTS:
Setting the throughput to SLOTS provides a method of opening
'time slot' for other RPM3 pairs operating in close proximity.
The effective streaming on-air throughput between a pair of
RPM3 is effectively reduced to approximately 3.6kbps (with/without
ACK). |
Figure 10: RPM3 operating in slots
throughput mode |
| |
| SLOTSW:
This setting effectively widens the SLOTS, reducing the over-air
throughput to approximately 600bps (with/without ACK). It allows
more RPM3 pairs to share the same frequency. Host should obey
CTS flow control signal from RPM3 when using SLOTS or SLOTSW
mode. |
Figure 11: RPM3 operating in slotsw
throughput mode |
| Certain fast file
transfer protocols like ZMODEM are not suitable for SLOTSW mode.
KERMIT or similar protocol which tolerates wider time gaps between
packets should be used in this mode. |
|
| |
| 4.2
REMOTE CONFIGURATION
Remote configuration of a RPM3 module is possible using the
REMOTE command from within the configurator. The remote RPM3
unit should be on or in auto-standby mode.
Initially the REMOTE command is used to enable and disable
the ability to remotely configure a module, as described in
section 3.2: User Configurable Command.
Once remote configuration is enabled the REMOTE command is
then used to issue configuration commands to a remote RPM3.
The format for the remote command then becomes:
|
REMOTE <SERIAL NUMBER> <COMMAND> <PARAMETER>
|
The <SERIAL NUMBER> of the remote RPM3 must be known
in order for the remote configuration request to be executed
on the appropriate RPM3 module.
|
| |
The <COMMAND> to be executed can be any of the following:
|
Baud 600,1200,2400,4800,9600,19200,38400,57600,115200
Unit 0 to 15
Site 0 to 7
Shdn on/off
Flow hw/none
Serdly 2 to 255
Retry 1 to 63
Signon on/off
|
The <PARAMETER> is optional, and if not specified
the setting for that command is returned and displayed.
|
|
| |
| 4.3
POINT-TO-MULTIPOINT
The RPM3 can be used for point-to-multipoint communications.
One module must be considered to be the master, which is used
to address up to 15 remote units in any one site.
During normal operation, the base unit can be set to address
another unit dynamically by entering the configurator and
using the ADDR command to change the unit address. Upon execution
of this command, provided the parameters are correct, the
configurator is exited immediately. A period ('.') is sent
to the connected host device to indicate that the change has
been registered and the RPM3 is now ready for communications
to the new unit address.
ADDR is very similar to the Unit command, except that ADDR
does not update the stored EEPROM unit value. As the EEPROM
has a limited number of write cycles, using ADDR for addressing
multiple units in a point to multipoint network is recommended.
Also, the ADDR command will exit the configurator immediately,
which is requires to resume communications very quickly.
|
| |
| 4.4
BROADCAST MULTIDROP
The RPM3 has a broadcast mutidrop mode which provides a mechanism
for building a large networks. This mode of operation is determined
by the configuration command keyword ACKMODE being set to
OFF.
In broadcast mutidrop mode, the RPM3 does not implement network
layer functionality related to data packet routing, acknowledgement
and retries. The connected host device should provide network
layer functionality.
The site code and unit address is still used by the radio
modem when working in broadcast multidrop mode. For a given
multipoint network all radio modems within a group must contain
the same site code and unit address.
|
| |
| 4.5
RADAR: DIAGNOSTIC TEST
Built into the configurator is a diagnostic test suitable
for range testing and link confidence testing. The Radar test
effectively sends a small request packet to a remote unit
then waits for a reply. The remote unit must not be in the
configurator otherwise it will not respond.
Upon receipt of a positive response from the remote unit,
a success is recorded before the process is repeated. This
test will continue indefinitely until it is ended by a key
press.
|
| |
| 4.6
SpacePort Modem Error Handling
The RPM3's radio decoder module is deliberately non bit error
tolerant, i.e. no attempt is made to repair corrupt data bits.
All of the redundancy in the code is directed towards error
checking. For an FM radio link using short packet lengths,
packets are either 100% or so grossly corrupt as to be unrecoverable.
By the same reasoning, the Host is not informed or sent corrupt
data since corrupt information is of little value. The RPM3
implements packet acknowledges, timeouts and re-transmission
accomplish reliable error handling.
|
|
| |
| Ordering Information
|
RPM3 issue 2 will
be supplied as standard.
Part
number
(European: 869.85MHz) |
Supply |
SMA
connector |
SMA
Antenna |
| RPM3-869-17 |
5V
|
-
|
-
|
| RPM3-869-17-3V |
3V
|
-
|
-
|
| |
|
|
|
| RPM3-869-17-SMA |
5V
|
Yes
|
No
|
| RPM3-869-17-3V-SMA |
3V
|
Yes
|
No
|
| |
|
|
|
| RPM3-869-17-ANT |
5V
|
Yes
|
Yes
|
| RPM3-869-17-3V-ANT |
3V
|
Yes
|
Yes
|
Part
number
(North American: 914.5MHz) |
Supply |
RPSMA
connector |
RPSMA
Antenna |
| RPM3-914-17 |
5V
|
-
|
-
|
| RPM3-914-17-3V |
3V
|
-
|
-
|
| |
|
|
|
| RPM3-914-17-RPS |
5V
|
Yes
|
No
|
| RPM3-914-17-3V-RPS |
3V
|
Yes
|
No
|
| |
|
|
|
| RPM3-914-17-ANT |
5V
|
Yes
|
Yes
|
| RPM3-914-17-3V-ANT |
3V
|
Yes
|
Yes
|
Note:
1. Standard RPM3 module will be
supplied with neither the connector nor antenna and RF pin
(2).
2. If an SMA (or
Reverse Polarity SMA) connector or 1/4 wavelength wire antenna
is soldered on the protruding PCB section for SMA connector,
then the RF pin (2) should be cropped with side cutters for
better RF performance.
3. If the RF output
is going to be taken from the RF pin (2) to on-board antenna
or connector on the host PCB (motherboard) via 50W
microstrip, the protruding section of the RPM3 PCB can be
cut along the width of the RPM3 to remove the redundant connector
section.
4. RPM3 is supplied with 7mm long
pins which need to be trimmed to mount the module as close
as possible to the host PCB (motherboard). Ideally, the black
coloured plastic spacer on the RPM3 pinheader should be touching
(resting on) the host PCB.
5. North American version can also be supplied
with SMA connector and antenna. However, only the RSPMA antenna
version is approved under FCC Part 15.249.
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| Appendix |
Figure 7: Example circuit
to make radio modem with DCE type RS232 interface
Click on the image for EXPANDED VIEW |
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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:
Licensing
policy manual
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*** End of RPM3 data sheet
***
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Figure 3: Physical
dimensions and pinouts
Figure 7: Example circuit
to make radio modem with DCE type RS232 interface