Occupancy & Temperature Node (OTN), Operations & Usage

5 Minute Read

| Overview

The Occupancy and Temperature Node is a product of the 75F system. It is tailor-made for BMS scenarios that demand micro zone level controls, that can override the existing schedules.

It provides efficiency in the BMS, where there is occupancy in space is dynamic like,

• A restaurant where occupancy varies during the day, and every other day.
• Work environments post Covid19 with cycled number of employees for the week. Predicting what part of the building gets occupied and what does not is a new requirement to handle.

| Features

• Occupancy and Temperature Node is powered by a 2 x AA battery and hence no wiring is required.
• The device is capable of communicating on a 75F proprietary RF network and does not need a gateway to connect to the rest of the system.
• Minimal BOM and hence is value for money, considering that each zone just needs one such device only without any cabling, gateway device, etc.
• The device can sense temperature and humidity with mechanical buttons and can still work as a thermostat if the device controls nothing.​​​​​​​
• The battery life is around 2 years.

| Specifications

• Humidity (typical +/- 2% RH), Temperature (typical +/- 0.2C) -optional.
• Occupancy Sensor based on Passive Infra-Red (PIR) with a detection range of 3m with a 120-degree conical angle.
• 2 x 10K Type-2 thermistor inputs with 2% accuracy -optional.
• 915 MHz Mesh IEEE 802.15.4-compliant, for communications to CCUv4.

| Wiring

The OTN which is powered by a 2 x AA battery requires no wiring as such for power, but it is provisioned with connectors to connect 2 x 10K Type-2 thermistor inputs, which is not an option by default but is ready for use based on the customer requirement

OTN Assembly

Provision for Thermistor Inputs

The provision for the thermistor inputs connection is achieved by a 3-pin connector,

• Solder or insert the thermistor wires to the rear of a male connector, which connects to the 3-pin connector.
• Pass the wires to exit through the passage in the front cover as shown.

3-Pin Connector

| Operations

OTN operates in two different modes under normal working conditions.

• Diagnostic mode -The default screen to access the different readings.

• Addressing mode - To set the pairing address of the OTN during pairing. 

| Usage

By default, when powered ON Diagnostic mode displays.

To access the Addressing mode,

• Press and hold down both the RED and BLUE buttons on the OTN simultaneously.

In the address mode, the last stored address blinks until the user presses any of the buttons again, after 2-3 seconds.  

Note: If the user short-presses the button within 2 seconds, then the address resets to 1000. Hence press the button after around 3 seconds, to start the pairing address from the last saved address.

From here, set the pairing address:

• Long Press (100ms minimum.) the RED button to INCREMENT the address by one count initially. 

• Long Press (100ms minimum.) the BLUE button to DECREMENT the address by one count initially.

To increment the address by different counts:

• First 10 counts, incremented in steps of 1 

• Next 10 counts, incremented in steps of 10 

• Next 10 counts, incremented in steps of 100 

• Last 10 counts, incremented in steps of 200

If at any point, the user releases the button, the address mode waits 10 seconds before it exits.

Note: This occurs to allow the user to change the address in case of a wrong entry. 

• Match the pairing address in the device to the pairing address in the CCU, the address sets automatically after a certain delay and displays a message 'Set' indicating the pairing address saved successfully.
• Press the buttons longer, for a smoother UI functionality.

| OTN Pairing Address Working