TR9277-EO Manual
Page 4 of 12
1. Light Harvesting Transmitter Description
The TR9277-EO is a wireless, energy-harvesting sensor that measures the following parameters:
•
Temperature: monitors room temperature in the range of 0-51°C (32° - 124°F).
•
Relative humidity in the range of 0-100% .
•
Carbon dioxide (CO
2
) in the range of 0-2000 ppm (pressure attitude corrected for increased
accuracy).
A button on the lower right edge of the sensor body can be used to go into test mode (when the
button is held down, see “Test Operating Modes”).
The TR9277-EO transmits to a receiver, controller or gateway that is typically used for environmental
control of a conditioned space. The TR9277-EO and receiving device must be within range,
preferably in the same room and installed within 80’ (24.4 m) of each other. For applications
exceeding 50’ (15.2 m) range, greater care must be taken to insure proper reception of the sensors
transmissions at the receiver, refer to sections “Test Operating Modes” and ‘Installing Wireless
Devices”.
Even with a brief exposure to light the sensor will operate; however for best results the sensor should
be mounted in a location with exposure of 4 hours of natural or artificial light on a daily basis.
The TR9277-EO transmits status telegrams that contain the information defined within an equipment
profile. The profile for this device is
A5-09-04
. Other profiles are in development to allow utilization
of the on-board pressure sensor and a dew point output.
2. Operation
In order to best manage power, the transmitting interval of the TR9299-EO is automatically managed
dependent on ambient light levels, rate of measurement change and amount of power stored in the
sensor. Telegrams are sent at the following intervals:
•
If the temperature change between last transmitted value and the current sample is > 0.6°C
(1.1°F), the sensor will transmit immediately.
•
If the RH value change between last transmitted value and the current sample is > 3%, the sensor
will transmit immediately.
•
If the CO
2
value change between samples is > 200 ppm, the sample and heartbeat rate shall
adjust to 300 sec (5 min) for 1 sample period
•
The CO
2
sample rate value is derived from three consecutive readings from the COZIR sensor
averaged with the previous transmitted value, level 1 and 2 only. For level 3, only the 3 readings
taken during the current sample are averaged.
