CWS900

900 MHz Configurable Wireless Sensor Interface
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CWS900

RetiredConfigurable

900 MHz Configurable Wireless Sensor Interface

Model:
CWS900
Item Number:
26179
Warranty:
1 year
Lead time:
14 days

Overview

CWS900 Wireless Configureatble Sensor Module, 900MHz

The CWS900 allows a sensor with a special connector to be used in a wireless sensor network; the special connector is available as an option for a large variety of sensors. (See the Compatibility information on the web page.)

The CWS900 contains an internal 900 MHz spread-spectrum radio that transmits data to the CWB100 Wireless Base Station or to another wireless sensor. The frequency of the CWS900's internal radio is commonly used in the US and Canada.

Key Advantages

Adapts Wide Variety of Sensors to Wireless Network

Technical Description

The CWS900 has a sealed connector for attaching one rain gage, wind sensor, temperature/RH probe, or another low power sensor. It measures analog voltages, low level AC, pulse counts, and can supply an excitation voltage for powering some sensors or making bridge measurements. The type of measurement that the sensor performs is configured using Wireless Sensor Planner, Network Planner, or DevConfig software. The CWS900 interfaces with the PC for configuration via the A205 CWS Sensor to PC Interface.

The CWS900 can route its transmissions through up to three other wireless sensors. A data logger is connected to the CWB100 base station for processing and storing the CWS900's data.

The CWS900 is battery powered using either alkaline batteries or a rechargeable battery and a solar cell.

Why Wireless?

There are situations when it is desirable to make measurements in locations where the use of cabled sensors is problematic. Protecting cables by running them through conduit or burying them in trenches is time consuming, labor intensive, and sometimes not possible. Local fire codes may preclude the use of certain types of sensor cabling inside of buildings. In some applications measurements need to be made at distances where long cables decrease the quality of the measurement or are too expensive. There are also times when it is important to increase the number of measurements being made but the data logger does not have enough available channels left for attaching additional sensor cables.

Note: The internal radio is not designed to move a lot of data quickly. It takes 15 to 30 seconds per hop when moving data from a sensor, through a sensor used as a repeater, and ending up at the base radio. Going through three repeaters could take a data packet anywhere from 45 to 90 seconds to get to the base radio.

Benefits

  • Allows a wide variety of sensors to be used in a wireless network
  • Internal frequency-hopping, spread-spectrum radio provides longer range and less interference
  • Battery powered
  • A reliable, low-maintenance, low-power method for making measurements in applications where cabled sensors are impractical or otherwise undesirable
  • Transmissions can be routed through up to three other wireless sensors

Specifications

Weather Resistance
IP67 rating for sensor and battery pack

(Battery pack must be properly installed. Each sensor is leak tested.)

Operating Temperature Range
-25° to +50°C
Operating Relative Humidity Range
0 to 100%
Power Source
2 AA batteries with a battery life of 1 year assuming sensor samples taken every 10 minutes.

(Optional solar charging available.)

Average Current Drain
300 μA

(with 15-minute polling and depending on attached sensor)

Analog Channels
SE1, SE2, SE3

(single-ended)

Analog Channels
DF

(differential)

Analog Input Range
-1 to +2.5 Vdc
Resolution
0.3 μV
Excitation Voltage
2.5 V, 3.3 V, 5.0 V

(20 mA maximum)

Excitation Voltage Accuracy
±2%

(-35° to +70°C)

Low-Level AC Input
20 mV minimum

(10 kHz maximum frequency)

Temperature Accuracy
±0.2ºC
Analog Measurement Accuracy
±(0.02% of reading + 2 µV)

(0° to 50°C)

Analog Measurement Accuracy
±(0.05% of reading + 2 µV)

(-35° to +70°C)

Bridge Measurement Accuracy (+2.5 V excitation only)
±(0.03% of reading + 3 µV)

(0° to 50°C)

Bridge Measurement Accuracy (+2.5 V excitation only)
±(0.07% of reading + 3 µV)

(-35° to +70°C) Not including sensor and measurement noise, and external bridge resistor errors.

Dimensions
15 x 6 x 4.5 cm

(5.9 x 2.4 x 1.77 in.)

Weight
184 g

(6.5 oz)

Switch Closure

Maximum Count Rate
100 Hz
Minimum Open Time
5 ms
Minimum Closed Time
5 ms
Maximum Bounce Time
4 ms
Maximum Number of Counts
Records 1,000,000 counts before it rolls over.

Internal 25 mW FHSS Radio

Frequency
902 to 918 MHz
Where Used
US and Canada
FHSS Channel
50
Transmitter Power Output
25 mW

(+14 dBm)

Receiver Sensitivity
-110 dBm

(0.1% frame error rate)

Standby Typical Current Drain
3 μA
Receive Typical Current Drain
18 mA

(full run)

Transmit Typical Current Drain
45 mA
Average Operating Current
15 μA

(with 1-second access time)

Quality of Service Management
RSSI
Additional Features
GFSK modulation, data interleaving, forward error correction, data scrambling, RSSI reporting

Related Resources

Connect With Us

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Phone Numbers
General: (435) 227-9000
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Corporate Address
815 W 1800 N
Logan, UT 84321
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Email Address
sales@campbellsci.com

As a trusted leader in measurement systems for more than 50 years, our top priority at Campbell Scientific has always been to provide the most accurate, reliable data for research and industry.