One-to-One Wireless Room Sensing System overview - Facility Explorer - LIT-12011663 - Wireless Device - WRZ: Wireless Room Sensing System

FX-WRZ Series One-to-One Wireless Room Sensing System Technical Bulletin

Facility Explorer
Product name
WRZ: Wireless Room Sensing System
Document type
Technical Bulletin
Document number
Revision date

The FX-WRZ Series One-to-One Wireless Room Sensing System is designed to interface with supported Facility Explorer BACnet® FX-PC Series controllers to provide wireless control of single-zone, room temperature, humidity, and occupancy applications. The FX-WRZ Series Sensor and FX-WRZ7860 Receiver combination is a functional equivalent to a network sensor, such as an NS-BTP7001-0 network sensor, but eliminates communication wiring, which is usually placed inside the wall.

A simple One-to-One wireless room sensing system consists of one to five FX-WRZ Series Wireless Room Sensors that communicate single-zone temperature and humidity data to an associated FX-WRZ7860 Receiver.

An FX-WRZ7860 Receiver interfaces with a single Facility Explorer FX-PCV or FX-PCG Controller.

See FX-WRZ Series Wireless Room Sensors for more information on the FX-WRZ Series Sensors .

Note: Multiple FX-WRZ Series Sensor models, a single model FX-WRZ7860 Receiver, and the FX-WRZSST-120 Wireless Sensing System Tool are available. All of these components have 10 mW transmission power.

The receiver meets the Institute of Electrical and Electronic Engineers (IEEE) 802.15.4 standard for low power, low duty cycle Radio Frequency (RF) transmitting systems and operates on the 2.4 GHz Industrial, Scientific, Medical (ISM) band. The One-to-One wireless room sensing system is designed for indoor applications only and should not be used for outdoor or inter-building applications.

The FX-WRZ Series Sensors and the FX-WRZ7860 Receiver operate as transceivers to create a bidirectional association between the sensors and the receivers that allows the sensing system to confirm data transmissions between the devices. The sensors and receivers must be located and installed properly to provide adequate RF signal strength to maintain this wireless association.

The maximum transmission range for indoor line-of-sight transmissions between an FX-WRZ Series Sensor and an associated FX-WRZ7860 Receiver is 150 ft (45 m). Taking into consideration RF signal absorption and reflection due to metal obstructions, walls, and furniture found in typical building interiors, the practical average indoor line-of-sight transmission range between a sensor and receiver is 100 ft (30 m). See Related Documentation for references to installation instructions.

To extend the range, use an FX-ZFRRPTK-H1 Series Wireless Field Bus Router and an FX-ZFRRPTK-H1 Power Supply. Using a repeater can help extend the transmission range through or around obstacles if theline-of-sight installation is not possible.

Important: The WNC1800/FX-ZFR1820 Pro Series wireless field bus system and associated hardware (excluding sensors) is not compatible with the FX-WRZ7860 wireless system. FX-WRZ sensors can be used in either FX-WRZ18xx (FX-ZFR or FX-ZFR Pro Series), or the FX-WRZ7860 system, but not in the same instance.
Note: The FX-ZFR182x-0 Pro Router/Repeater is not compatible with the FX-WRZ7860 system.
Figure 1. One-to-One Wireless Room Sensing applications

The sensors and receivers are associated to each other with matched unique RF addresses. The RF addresses are established on the devices by setting the switches on address DIP switch blocks on the devices. After the sensor/receiver associations are created, the sensors transmit the following data at 60-second intervals:

  • sensed zone temperature occupancy (PIR) and humidity (depending on the FX-WRZ Series Sensor model)
  • setpoint temperature (depending on the FX-WRZ Series Sensor model)
  • requested zone occupancy override

See Radio Frequency Addresses for One-to-One Wireless Sensing Applications, Setting the FX-WRZ7860 Receiver RF Address, and Setting the FX-WRZ Series Sensor RF Address for more information on setting RF addresses in One-to-One sensing system applications.

In One-to-One applications with two to five sensors, the receiver passes all the sensors’ data to the controller. The FX-PCV or FX-PCG controller can be configured to either average the sensors’ temperature or humidity input independently, or select the highest or lowest sensed temperature or humidity for control of the target zone. See the appropriate controller or system documents for additional information.

Note: For FX-WRZ Series Sensors with an LCD display, the humidity value may appear as 0.0% when the sensor is joining a network. This condition is transitory and does not transfer to the Building Automation System (BAS).

The FX-WRZ Series Sensors and the FX-WRZ7860 Receiver also indicate signal strength and other wireless diagnostic data.

Important: The One-to-One wireless room sensing system, FX-WRZ7860 Receiver, and FX-WRZ Series Sensors are not designed or intended for use in mission-critical or life/safety applications.
Important: The FX-WRZ Series Sensors and the FX-WRZ7860 Receiver are not compatible with the WRS-TTx Sensors and the TE-7820 or TE-7830 Receivers.