DR9011/DR9021 Point to Point Wireless Data Acquisition System Copyright © 2008 Wilkerson Instrument Co., Inc All rights reserved.

DR9011/DR9021 Point to Point Wireless Data Acquisition

System

Copyright © 2008 Wilkerson Instrument Co., Inc All rights reserved

• A DR9011 Remote Transmitter Can Send Analog and Contact Status Up to 20 Miles to a DR9021 Receiver

• Sends Analog and Contact Status Data in One Direction

• Analog Inputs Available For DC Voltage or DC Current, RTD, or Bridge. Dual Channel DC – Single Channel RTD or Bridge

• Four Digital Inputs For Contact Closure or NPN Transistor Status

• Power 10 – 30VDC

DR9011/DR9021 POINT-TO-POINT WIRELESS DATA ACQUISITION


DR9011 Transmitter

2

DR9011/DR9021 POINT-TO-POINT

WIRELESS DATA ACQUISITION

• Dual DC Voltage or Current Inputs—Individually Isolated

• Dual Channel DC Inputs Can Have Mixed Inputs

• 100 Ohm Platinum RTD Input – 2 or 3 Wire

• Bridge Input – Built In Precision 10VDC Excitation For Four 330 Ohm Bridges


DR9011 Transmitter

3

4

Typical Interface to Discrete Input

DR9011/DR9021 POINT-TO-POINT

WIRELESS DATA ACQUISITION



• Dual 4-20mA Outputs

• Dual DC Inputs Have An Output Proportional to Each Input

• Single Analog Inputs Have Dual 4-20 mA Outputs – Each Proportional to The Single Input

• Four Optically Isolated NPN Transistor Discrete Outputs

• Power 85 – 230VAC, 12VDC, or 24VDC


DR9021 Receiver

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6


Two Typical Interfaces to Discrete Output


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Typical Relay Interface to Discrete Output



Frequencies

915 MHz Band

908 or 922 MHz

2.4 GHz Band

2.4000 - 2.4835 GHz

Spread Spectrum Type

Frequency Hopping, Direct FM

7 Hop Sequences Each Frequency Band

Range / Line of Sight 915 MHz Band

Up to 20 Mi. 2.4 GHz Band

Up to 10 Mi.

I/O Data Rate Tx to Rx 9600 bps

Data Update Rate 9/Sec

RADIO

Copyright © 2008 Wilkerson Instrument Co., Inc All rights reserved8

Antenna Data

Radio frequency currents flowing in an antenna element

creates a magnetic field around the conductor. This

magnetic field radiates through space and induces a

small current in any conductor it passes.

The small current created in the receiving antenna of

interest is processed by the radio receiver to accomplish

the required task.


Antenna Data

• Transmit and receive antennas’ elements must be aligned in the same direction

• Antenna gain is stated as gain relative to a reference antenna

• Reference “antenna” is a point (isotropic) source which radiates in a perfect sphere

• Gain is achieved by distorting the perfect sphere to radiate more in a given direction

• The isotropic antenna is assigned a gain of 1• Practical antennas have their gain referenced to the

isotropic source.Copyright © 2008 Wilkerson Instrument Co., Inc All rights reserved

10

Antenna Data

• The gain of an antenna, in a given direction, can be defined as “for a given input power, the gain of an antenna is the power radiated by the antenna divided by the power radiated by an isotropic source.”

• Gain is usually expressed in decibels which is expressed by Gain = 10log (power radiated by antenna) / (power radiated by isotropic source). An i indicates gain relative to an isotropic source (dBi).

• For a gain of 2 10log(2/1) = 10 X 0.3 = 3dBi• For a gain of 10 10log(10/1) = 10 X 1 = 10dBi• Antennas are perfectly reciprocal – Gain is the same for

transmitting and receiving.Copyright © 2008 Wilkerson Instrument Co., Inc All rights reserved

11

915MHz Band Antennas

Short Range Antennas

Small vertical antennas are used for short range communications

7” vertical antenna for indoor mounting. Mounts by screwing on SMA bulkhead connector. Articulated 90 degree joint allows horizontal or vertical connector to be used. Line of sight range about 1000 to 1500 feet. 2.1dBi gain

2 3/4” vertical antenna for outdoor mounting. Mounts on a special bulkhead connector . A bracket is available for mounting on a flat vertical surface or a mast. Line of sight range about 1000 to 1500 feet. 2.1 dBi gain

Vertical omni-directional antenna for outdoor mounting. Type N female connector to accept coaxial cable. Has bracket for mounting on 1 ½” mast. Line of sight range several miles.

6dBi and 8.5dBi gain models. 27” and 60” lengths.

Copyright © 2008 Wilkerson Instrument Co., Inc All rights reserved 12

915MHz Band Antennas

Long Range Antennas

Yagi antennas with high gain are used for long range communications.

8 dBi gain 18” length




2 Stacked Yagi 17 dBi gain 48” lengthCopyright © 2008 Wilkerson Instrument Co., Inc All rights

reserved 13

Antenna Beam Patterns

Vertical beam pattern of a

long range vertical antenna. From

the top it appears as a doughnut.

From the side it has the radiation

pattern shown.

Horizontal beam pattern of a yagi antenna. Note the insensitivity from the rear.

8.5dBi gain 52” 4241 11 dBi gain 21” length 4078 Copyright © 2008 Wilkerson Instrument Co., Inc All rights reserved 14

Need More Information!

Wilkerson Instrument Co., Inc. 2915 Parkway Street Lakeland, FL 33811

Toll Free: 800-234-1343 Phone: 863-647-2000 Fax: 863-644-5318 Email: [email protected]

Complete documentation is available for all Wilkerson Instrument Co. products at www.sensorad.com and www.wici.com.


mailto:[email protected]

http://www.sensorad.com/

http://www.wici.com/

DR9011/DR9021 Point to Point Wireless Data Acquisition System Copyright © 2008 Wilkerson Instrument Co., Inc All rights reserved.

Documents

direction antenna gain

wilkerson instrument

rights reserved slide

antenna power

dbi gain models

isotropic antenna

high gain

reciprocal gain