Occupancy & Temperature Node (OTN), Operations & Usage

5 Minute Read

|Overview

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 occupancy in a space is dynamic like,

• A restaurant where occupancy varies during the day, and every other day.
• Work environments post Covid19 where the employee numbers are cycled during the week, and  predicting what part of the building get occupied and which will not, is a new requirement to handle.

|Features

• Occupancy and Temperature Node is powered by 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.
• The product has 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 and has mechanical buttons and can still work as a thermostat if we are not controlling anything.​​​​​​​
• The battery life of this product is expected to be 2 years.

|Specifications

• Humidity (typical +/- 2% RH), Temperature (typical +/- 0.2C) -optional.
• Occupancy Sensor based on Passive Infra-Red (PIR) with detection range of 3m with 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.

|Operations

There are two modes of operations under normal working conditions of the OTN (Occupancy & Temperature Node)

• Diagnostic mode - Which is the default screen where all the different readings can be accessed.

• Addressing mode - This is where the pairing address of the OTN is set during pairing. 

|Usage

By default when the OTN is powered ON it is in Diagnostic mode.

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 the 2 seconds, then the address resets to 1000. Hence, it is preferable to press the button after around 3 seconds, in order to start the paring address from the last saved address.

From here, to 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 address by different counts:

• First 10 counts, incremented in steps of 1 

• Next 10 count,  incremented in steps of 10 

• Next 10 counts, incremented in steps of 100 

• Last 10 counts,  incremented in steps of 200 

Note: If at any point, the button is released, the address mode waits 10 seconds before it exits. This occurs to allow the user to change the address in case of a wrong entry. 

Once the pairing address is matched with the pairing address in the CCU,  the address is set automatically after certain delay, with a display message 'Set' indicating the the pairing address save successfully.

The longer the button is pressed faster the increments are, and smoother the UI functionality. 

|OTN Pairing Address Working