MDR210A-485
900 MHz. Frequency Hopping RS-485 Master/Slave auto-sensing
radio interface.
Description
The MDR210A-485 uses an embedded 100-milliwatt, frequency-hopping
wireless modem that provides communication between a local RS485 network
and a remote network of RS485 connected devices. The MDR210A-485 will
automatically sense the direction of data flow and switch the RS485 and Radio
devices accordingly. The MDR210A-485 can be placed in a network of RS485
devices and appear as a slave repeater of remote RS485 devices or it can be
placed in a network of one or many RS485 slaves and act as the RS485 repeater
of a remote master. The radio operates within the 900 MHz ISM Band under
Part 15 of the FCC Rules and Regulations.
The MDR210A-485 operates at 19200 Baud at either odd parity or no parity.
Dipswitches select parity and one of 7 radio networks. Radios operating together
must have the same radio network address (1-7 set by switches labeled A0-A2).
Select a different radio network address to prevent interference from nearby
networks that are not sharing information. The default radio network for Rooftop
applications is 5. The user may choose another network address (1-7) if desired.
While all radios in a network must have the same network address, they do not
have to have the same parity. The parity is local to the RS485 serial port on the
MDR210A-485 only. Parity information is not transmitted or received.
Radio network selection 0 (A0, A1, A2 all set to 0) selects a special network
setup. When network address setting 0 is selected, the pre-programmed radio
network parameters are used. These parameters are user and application
specific and must be set at the factory for specific OEM applications.
The MDR210A-485 can also be used as a general purpose RS485 half duplex
radio interface operating at 19200 Baud at either odd or no parity (dip switch
selectable).
PARAMETER
Supply Voltage
Supply Current
Baud Rate
MIN
6.0
70
-
TYP
12
-
MAX
24
200
-
UNITS
Volts
mA
19200
Baud
PIN
1
2
SIGNAL
TR-
TR+
DESCRIPTION
RS485 transmit/receive negative I/O
RS485 transmit/receive positive I/O
Common
3
GND
3
Features
·res
RS485 Master/Slave auto-sensing radio interface.
·
Built in 900MHz frequency hopping radio for long-range
wireless interface.
·
·
·
Provides remote capability to RS485 Modbus networks.
Automatically senses Master or Slave data flow.
Multiple radios allow many remote RS485 networks to coexist
logically.
·
·
·
·
·
·
Provides means to connect legacy RS485 devices to wireless.
Range Indoor: 600’ to 1300’
Range Outdoor: 7mi. with dipole, >20 mi. w/high gain antenna.
LED power and activity indicator.
Configuration parameters set by dipswitch.
Low power, 6-24 VDC at 200 milliamp transmitting, 70 milliamp
receiving.
·
Astron AXH900RP SMA R Reverse Polarity SMA 6.5”
Antenna.
General
MDR210A-485
Frequency Range
Type
902 to 928 MHz., unlicensed ISM Band
Frequency Hopping Spread Spectrum Transceiver
Direct FM
Frequency Control
Transport Protocol
Channel Capacity
Serial Data Interface
Transparent networking
Hops through 25 channels. Up to 65,000 network identifiers.
Asynchronous RS232 levels. CMOS (TTL) Signals, 5V, 3.3V Tolerant
Configurable from 2400-57600 bps
Serial Interface Baud
Rate
Data Throughput
9600 bps
Network Topology
Point – multipoint, point-to-point multi-drop transparent networking
Performance
Channel Data Rate
Transmit Power Output
Rx Sensitivity
10k or 20k bps respectively (vary with data rate)
100mW
-110dBm or –107dBm Respectively
Range*
Indoor: 600’ to 1500’ Outdoor: 7 mi. with dipole, over 20 mi. with high gain antenna
70 dB at pager and cellular phone frequencies
Interface Rejection
*Range calculations are for 9600 baud line of sight. Actual range will vary based upon specific antenna selection and
environment
4
9XSTREAM-192/96 Radio
Introduction
The 9XSTREAM-192/96 radio is a 100-milliwatt frequency hopping wireless modem that
communicates with other equipment using a standard 19200 or 9600-baud asynchronous serial
data stream. The radio is half-duplex and can sustain a continuous data stream at the specified
data rate. The 9XSTREAM operates within the 900 MHz ISM Band under Part 15 of the FCC
Rules and Regulations.
IMPORTANT: The 9XSTREAM radio has been certified as a module by the FCC for integration
into OEM products without further certification being necessary (as per FCC section 2.1091.) The
OEM must satisfy the following requirements in order to comply with FCC regulations:
The system integrator must ensure that the external label provided with this device is placed on
the outside of the final product.
In order to comply with the FCC RF exposure requirements, the 9XSTREAM may be used only
with approved antennas that have been tested with this radio and a minimum separation distance
of 20 cm must be maintained from the antenna to any near by persons. The OEM must also
include a statement in the final product manual, informing users of the requirement to maintain 20
cm separation from the antenna to any near by persons. If the OEM integrates the 9XStream into
their final product, where the final product utilizes a non-approved antenna or is classified as a
portable device per FCC Section 2.1093 (less than 20 cm separation distance between the
antenna to any near by persons,) the OEM is responsible for obtaining a separate authorization
on the final product.
The 9XSTREAM radio requires a regulated 5-volt, 200mA supply for operation. Any voltage
higher than 5.5 volts will damage the radio.
Approved Antennas
Mfr Model
Dimensions
Freq
Gain Type
Connector
Astron AXQ900 PTL
Astron AXH900RP SMA R 902-928
MaxStream 900CDAN
902-928
2dBi Omni
2dBi Omni
2dBi Omni
MMCX 3”
Reverse Polarity SMA 6.5”
Integrated 3”
902-928
External Label:
This device contains transmitter module
FCC ID:OUR9XTREAM. The enclosed
device complies with Part 15 of the FCC Rules.
Operation is subject to the following two
conditions: (1) This device may not cause
harmful interference, and (2) this device
must accept any interference received,
including interference that may cause
undesired operation.
5
9XStream Frequency Hopping Data Radio
FCC Compliance Warning:
Changes or modifications to the 9XStream Data Radio not expressly approved by MaxStream,
Inc. could
void the user’s authority to operate this product.
Note: This equipment has been tested and found to comply with the limits for a Class B digital
device, pursuant to part 15 of the FCC Rules. These limits are designed to provide reasonable
protection against harmful interference in a residential installation. This equipment generates,
uses, and can radiate radio frequency energy and, if not installed and used in accordance with
the instructions, may cause harmful interference to radio communications. However, there is no
guarantee that interference will not occur in a particular installation. If this equipment does cause
harmful interference to radio or television reception, which can be determined by turning the
equipment off and on, the user is encouraged to try to correct the interference by one or more of
the following measures:
? R?eorient or relocate the receiving antenna.
? I?ncrease the separation between the equipment and receiver.
? C?onnect the equipment into an outlet on a circuit different from that to which the receiver is connected.
? C?onsult the dealer or an experienced radio/TV technician for help.
This device complies with part 15 of the FCC Rules. Operation is subject to the following two
conditions:
1. This device may not cause harmful interference, and
2. This device must accept any interference received, including interference that may cause undesired
operation.
6
Antenna
Antenna Connector MMCX Female
Antenna Impedance 50 Ohms unbalanced
Approved Antennas Integral wire antenna (factory installed)
Astron AXQ9PRLMMCX – 1/4 wave flexible whip
Astron AXH900 RP SMAR – 1/2 wave flexible whip, SMA
Serial Port Scanning
The Scan Function is provided to assist the user when they are unsure which
communication port the MDR210A-485 is attached to or what baud rate it has been set
to. The Scan Function will attempt to communicate with the MDR210A-485 over every
port installed on the PC at every allowed baud rate. While this is not a fast process, it
does allow the recovery of a device whose configuration is unknown. If the Scan
Function is unable to determine the port which the MDR210A-485 is attached to, the user
will be notified. The user should then ensure that no other application has the
communication port in use before re-attempting the Scan.
Application Fields
COM Port - Specifies which PC communication port the MDR210A-485 to be
configured is attached.
Scan - The scan function iterates each available PC communication port looking for an
attached MDR210A-485. If an MDR210A-485 is found, its COM Port and current Baud
Rate values are provided.
Network ID - All communicating MDR210A-485s must be programmed to the same
Network ID. The valid values are from hexadecimal 1 to FFF.
Hop Table - All communicating MDR210A-485s must be programmed to the same Hop
Table. The valid values are 0 to 6. Independent networks in the same vicinity should use
different Hop Tables to minimize packet collisions.
Baud Rate - This is the desired communication Baud Rate between the host and the
MDR210A-485.
Setup - Send the currently selected values to the MDR210A-485 attached to the specified
communication port.
Close - Exits the Application.
Networks
There are seven available networks (Hop Tables). Each network utilizes a different
pseudo-random hopping sequence to navigate through the shared hopping channels. In
the event that two modules from different networks collide on a channel (because they
7
hop in a different sequence) the two modules will jump to separate channels on the next
hop. Using networks, multiple module pairs can operate in the same vicinity with
minimal interference from each other. The network parameter is user-definable using the
MDR210A-485 Set-up Hop Table.
Module Address
Module Addresses provide another level of addressing among the MDR210A-485
modules. Each module in a network can be configured with a 16-bit Module Address to
establish selective communications within a network. This address is set to 65535 values
using the MDR210A-485 Set-up Hop Table command.
All modules with the same Module Address can transmit and receive data among
themselves. Any modules on a network with different Module Addresses will still detect
and listen to the data in order to maintain network synchronization. However, they will
not send the data to their serial ports if their Module Addresses do not match the Module
Addresses of the transmitter.
Data Validity
The first data packet transmitted contains all bytes that accumulated in the data buffer
while the header (see Figure 2a below) was being sent. After the first data packet is sent,
another header will be sent if data is available in the buffer. The header is followed by
another data packet. The second data packet (and all subsequent data packets) will
consist of data that accumulated in the buffer while the previous data packet and header
were being sent (see Figure 2a). The size of each data packet can vary up to 64 bytes.
This progression can be seen in Figure 2b.
Sent Data:
Data
Data
Header
Packet 1
Header
Packet 2
Header
Collect
Data for
Packet 1
Collect Data for Packet 2
Collect Date for Packet 3
Group Data into Packets:
8
Figure 2a – Generation of Data Packets
Data Validity (Cont.)
Header
Data from Buffer
Data
CRC
No Data
To Idle Mode
Figure 2b – Transmit Mode Description
To verify data integrity, a 16-bit cyclic redundancy check (CRC) is computed for the
transmitted data and attached to the end of each data packet before transmission. The
receiver will then compute the CRC on all incoming data. Any received data that has an
invalid CRC is discarded.
Glossary
Data Buffer – Collects incoming serial data prior to over-the-air data transmission. The
data buffer can hold up to 132 bytes at a given time.
9
Data Packets – A grouping of data to be sent over-the-air. Each data packet contains a
header and data that is collected from the data buffer. The size of the packets varies up to
64 bytes depending on how many bytes of data are in the data buffer.
Glossary (cont.)
Frequency Hopping Spread Spectrum (FHSS) – Method employed by the MDR210A-
485 module which involves transmitting data over several different channels in a specific
channel hopping sequence known by the transmitter and the receiver(s).
Half-duplex – A mode for radio operations. Radios that operate in half-duplex are able
to either transmit data or receive data at a given time, but cannot do both simultaneously.
When one module is transmitting, all modules within range listen to the transmission and
will only transmit when the transmission is complete.
Module Addresses – Provides a layer of addressing among modules. Modules with the
same Module Addresses can communicate together.
Networks – Provides a layer above Module Addresses for communicating between
modules. Each network has a unique hopping sequence that allows modules on the same
network to remain synchronized together.
RS-232 logic – Standard logic levels implemented in devices using the RS-232
communication protocol.
Sensitivity – A measurement specification that describes how weak a signal can be
(in dBm) and still be detected by the receiver.
Serial Data – Data that enters the MDR210A-485 module through its serial port.
Start bit – A low UART signal to signify the beginning of an eight-bit data sequence.
Stop bit – The last bit in a UART data sequence. The stop bit is high and indicates the
end of an eight-bit data sequence.
Synchronization – Synchronization is used to ensure that the transmitter and receiver are
communicating properly with each other and following the same channel hopping
sequence.
Transmission Latency – Time required to send a packet of data. This value is
dependent on the number of bytes being sent and the baud rate of the module.
Transmit Mode – Mode of operation in which over-the-air data can be transmitted from
a module to other modules.
10
Application Notes
Why does Sensitivity Matter?
Receiver sensitivity is the lowest power level at which the receiver can detect a wave and
demodulate data. Sensitivity is purely a receiver specification and is independent of the
transmitter. As the wave propagates away from the transmitter, it attenuates as the
distance increases. Lowering the sensitivity on the receiver (making it more negative)
will allow the radio to detect weaker signals, and thus increase the transmission range.
Sensitivity is vitally important since even slight differences in receiver sensitivity can
account for large discrepancies in the range. To better understand this relationship, the
following example is provided.
Example:
Compare the MDR210A-485 module (with –110dBm sensitivity) to a commercial radio
receiver with a sensitivity of –90 dBm. The Friis transmission formula can be used to
calculate received power (or signal strength) at any receiver location under line-of-sight
conditions. This formula is given by
P( t ) x G( t ) x G( r ) x l²
P( r ) =
F( s ) x 4 pr ²
P(r) = received power (mW)
P(t) = transmitted power (mW)
G(t) = gain of transmit antenna (linear)
G(r) = gain of receive antenna (linear)
F(s) = fading margin (linear)
l = wavelength (meters)
r = distance between Transmitter and Receiver (meters)
The following values were used to compare the range limitations of these modules:
P(t) = 100mW
G(t) and G(r) = 2dB, or 1.585 linear
l = 0.333 meters
F(s) = 21dB, or 125.89 (experimentally determined.
The table below demonstrates the power received at the receiver over the specified range
between the TX and RX antennas, assuming line of sight conditions.
11
Application Notes (cont.)
Detectable
Detectable by
by
Range
Received
(meters)
Power
MDR210A-485 Commercial
Radio
100
500
-68.526 dBm
-82.506 dBm
-88.526 dBm
-92.048 dBm
-102.506 dBm
-106.588 dBm
-108.526 dBm
YES
YES
YES
YES
YES
YES
YES
YES
YES
YES
NO
NO
NO
1000
3000
5000
8000
10000
11265
NO
(7miles) -109.559 dBm
12000 -110.805 dBm
YES
NO
NO
NO
Since the range doubles every 6dB, the 20dB sensitivity difference in radios corresponds
to 2^(20/6) = 10.08 times the range using the MDR210A-485 radio!
12
Appendix A – Specifications
General
Frequency Range
902 to 928 MHz, unlicensed ISM Band
Frequency Hopping Spread Spectrum
Transceiver
Type
Frequency Control
Transport Protocol
Direct FM
Transparent Networking
Hops through 25 channels. Up to 65,000
NetIDs.
Channel Capacity
Serial Data Interface
Serial Interface Baud Rate
Data Throughput
Asynchronous RS-232 levels
?????
?????
Performance
10k or 20k bps Respectively (vary with data
rate)
100mW
Channel Data Rate
Transmit Power Output
Rx Sensitivity
-110 or –107 dBm Respectively
Indoor: 600' to 1500' Outdoor: 7mi. With dipole,
over 20 mi. with high gain antenna
Range*
Interference Rejection
70 dB at pager and cellular phone frequencies
Power Requirements
Supply Voltage
5 VDC +/-0.3V
Current Consumption
Tx - 170 mA nominal, Rx - 50 mA nominal
Physical Properties
Board Size
Weight
1.6” x 2.7” x .35” (4.06 x 6.86 x .89)cm
8 oz. (24g)
Connectors
Operating Temperature
Operating Humidity
11 pin 0.1” spaced male berg type header
-40° to 85° C
10% to 90% (non-condensing)
Antennas
Antenna Connector
Approved Antennas
MMCX Female
????
*Range calculations are for 9600 baud radio line of sight. Actual range will vary based upon specific board integration,
antenna selection, environment and the OEM’s device.
Antenna
Antenna Connector MMCX Female
Antenna Impedance 50 Ohms unbalanced
Approved Antennas Integral wire antenna (factory installed)
Astron AXQ9PRLMMCX – 1/4 wave flexible whip
Astron AXH900 RP SMAR – 1/2 wave flexible whip, SMA
13
FCC Compliance Warning:
Warning: This device complies with part 15 of the FCC Rules.
Operation is subject to the following conditions:
1. This device may not cause harmful interference, and
2. This device must accept any interference received, including
interference that may cause undesired operation.
14
|