Page is loading ...
General Description:
The Air-485 modems are high performance 900MHz FHSS industrial grade long range wireless
modems that are designed to provide reliable data link to RS485 serial devices and to offer a
simple cost effective alternative to running costly RS485 data cables, specially in commercial
environments that make wire connections challenging or impractical.
The AIR-485 modems are optimized to work with Cansec’s SmartLock, Maesto and Zodiac
products but can be used with any product that support RS485 communication.
They provide wireless link which are totally transparent to the connected devices.
Features
Plug and Play communications
Unlike most wireless modems the AIR-485 modems do not require the use of a PC or laptop
and complicated software to set up the radio and communication parameters. Instead the AIR-
485 modems are configured through simple DIP switch settings (see Figures 1 and 2 below).
Long Range
Indoor/Urban: up to 1300 ft (400m) depending on antenna height and RF interference
Outdoor line of sight: up to 10 Km (6 miles) with standard antenna provided
USB and RS-485 support
The AIR-485 units support both USB and RS-485. When connected to PC via USB the device is
powered from the USB. When connected to an RS485 data cable, an external power supply
must be used...
The
unit
automatically detects the type of connection and configures itself
automatically. Support for both types of connections provides great flexibility in accommodating
almost every imaginable configuration (samples provided later in this document.)
Adjustable RF Power Level
Four output power levels 10, 250, 500 and 1000 milliwatts can be easily set in the field using
two DIP switches. The RF power level should be set higher as needed for longer operation.
Note that setting the RF power to a high level when doing testing at 2m can overload the
receiver and cause erratic operation.
Visual Signal Level indication
The built in continuous signal strength diagnostic test that could be initiated from any remote
AIR-485 modem reference to the base modem provides real time signal strength indication
through three green LEDs (Figure 2). This feature helps the installers tremendously in terms of
choosing the correct location and elevation for the modems and aligns the antennas for
maximum signal reception. Also eliminates the need for expensive tools and power meters.
Multiple network support
Because the range of the AIR-485 modems can be up to 10km (line of sight), it is possible that
installations in close proximity could interfere with each other. To address this, the units have
two DIP switches which allow up to 4 Network ID numbers to be specified. Modems which are
set to ID 1, for instance, will only recognize transmissions from modems with a matching ID
number.
Secure data communications
The AIR-485 modems use 128bit encryption to insure that the data integrity is not compromised.
Setup
DIP Switch Settings
There are two sets of DIP switches which must be set.
Figure 1
SWITCH
POSITION OPERATION
1
DOWN SETS MODE TO MASTER
UP SETS MODE TO SLAVE
2
3
DOWN LOW
DOWN POWER
UP MEDIUM
LOW
DOWN POWER
DOWN MEDIUM
UP POWER
UP HIGH
UP POWER
4
DOWN NORTH AMERICA
UP AUSTRALIA
5
DOWN 9,600 BAUD (hardwired)
UP 38,400 BAUD (hardwired)
6
MUST BE DOWN
7
DOWN NORMAL MODE
UP SIGNAL STRENGTH TEST
8
MUST BE DOWN
1) NOTE: Any time DIP switch settings are changed, the RESET switch must be pressed.
2) LINK LED (Figure 1) – For a Master unit, if this LED is on SOLID, it indicates that the
unit is successfully connected to at least one Slave. For a Slave unit, this LED indicates
that it is successfully connected to a Master.
3) TX\RX LEDs (Figure 1) – These LEDS indicate the transmission and receipt of data.
What a surprise!
4) When the AIR-485 Master is connected to a PC via USB it is powered from the USB port.
Because
of the limited current available, only the two lowest power setting should be
used. If a higher transmit power setting is required, you need to use an optional plug- in
power supply.
5) Switch 1 – For Point To Point, set one unit to Master and the other to Slave. If one
is
connected
to the PC via USB, it must be set to Master. For Multi-Point, set the unit
connected to the PC (via RS-485 or USB) as Master and set the field units as Slaves.
6) Switches 2 and 3 – The factory default setting is Low Power. If the distance between the
Master and Slave(s) is MORE THAN 100 feet, set the switches to HIGH POWER on
both the Master and Slave(s). Note that the Master and Slave(s) should always be set
to the SAME power level. If the distance from the Master to the Slave(s) is LESS THAN
100 feet, start with both units set to LOW POWER and progressively increase the power
level
until
you get an acceptable signal level (see Signal Level Test below). This is
important as
using
a
power setting that is too high for a Master and Slave which are in
close proximity will result in a poor communications link.
7) Switch 4 – Set to DOWN (default) for North America. Set to UP for Australia.
8) Switch 5 – Used to set the hard wired baud rate. The baud rate through the air is fixed
and is 115K bps.
9) Switch 6 – Must be DOWN.
10)
Switch 7 – Applies to Slave units only. When this switch is UP, the unit is in Signal Test
Mode. In this mode, the Slave unit interrogates the Master which returns a diagnostic
message which allows the to measure the received signal. The three green LEDs
display this relative signal strength (see below).
11)
Switch 8 – Must be DOWN.
Figure 2
RS-485
NETWORK
ID
SIGNAL
STRENGTH
GND
SIGNAL A
SIGNAL B
NETWORK ID SIGNAL STRENGTH
1 2 3 4
NO SIGNAL OK
STRONG VERY
STRONG
12. Signal Strength Indicator LEDs – These LEDs ONLY indicate the strength of the
received signal when DIP switch 7 (Figure 1) is UP. The rule of thumb is that more
LEDs are better. However, as long as you have at least ONE LED and it is on SOLID,
there is a solid data connection. In NORMAL mode, the lower LED will be on SOLID
and indicates that the unit is powered on.
Outdoor Installation
For outdoor applications, use the CA-AIR485-N which consists of an AIR-485 unit housed in a
plastic Nema enclosure c\w external antenna. This configuration is temperature rated for -40oC
to +85oC. The front of the enclosure is transparent allowing the status LEDs to be checked
without opening it.
Applications
ƒ Access Control
ƒ Security
ƒ Industrial Controls and Robotics
ƒ Oil Fields
ƒ Agriculture
Specifications
ƒ
Operating Frequency Range
902 - 928 MHz
ƒ
Number of RF Channels
50
ƒ
Modulation
FSK
ƒ
Serial Data Rates
9600 , 38400 kbs
ƒ
RF Data Transmission Rate
115.2 kbs
ƒ
Receiver Sensitivity
-102 dBm 0.00001 BER @ 115.2 kbs
ƒ
Transmission Output Power
10, 250, 500 and 1000mW
ƒ
Power Requirement
USB Power (low RF output) or
12VDC 1A (high RF output)
ƒ
Network Topologies
Point-to-Point, Point-to-Multipoint
ƒ
Optimum Antenna Impedance
50 Ohm
ƒ
Antenna
3dBi
ƒ
Antenna connection
RPSMA
ƒ
Peak Transmit Mode Current@1 W
1200 mA
ƒ
Base Operating Receive Current
105 mA
ƒ
ƒ
Remote Operating Receive Current
Operating Temperature Range
60 mA
-40oC to +85oC
ƒ
Dimensions
11.2cm x 9.0cm x 2.7cm
ƒ
Weight
220 Gm
/
