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Not all parts of a room experience similar conditions, we at 75F truly believe in that. Hence, to monitor the conditions of a room, providing the necessary conditioning monitoring with only one sensor is not sufficient.
To tackle the problem 75F introduced a portfolio of sensors that can be mounted at different parts of the room, but the problem ended there.
The Room controllers/ master devices, SmartNode, SmartStat, and HyperStat were provided with just one port to accommodate just one sensor, apart from the onboard ones (as applicable).
This led to bringing in the daisy-chaining capabilities in all the latest sensor releases, and a wiring harness to support the daisy-chaining of the sensors in a bus network.
| Wiring Harness for Daisy Chaining
This wiring harness comprises a 3-wire female connector at one end, and two male connectors at the other end. This can be plugged into the daisy chain ports provided in the sensors for power and communication.
Daisy Chaining of sensors is achieved, when the above wiring harness is combined with the 3 Pin to 3 Pin cable of lengths 18 inches, 20, 30, and 50 feet.
| Daisy Chaining Rules
Below are the rules to be followed while daisy-chaining sensors in a bus:
- A maximum of 4 one wire interface devices can be connected in a bus
- A maximum of 4 multi sensors can be supported in a bus
- A maximum of 3 duct sensors can be supported in a bus.
- A maximum of 1 differential pressure can be supported in a bus.
- A maximum of 1 device of Ceiling/Flush/Wall sensor can be supported in a bus.
Below is an illustration of the daisy chaining example for the Multi-Sensor
Daisy Chaining Multi-Sensor
When Daisy Chained
- Not more than 4 multi sensors can be daisy chained in a Bus.
- The Temperature, CO2, and Humidity values of the sensors in the bus are averaged for the master device.
- The occupancy in the master device results, when at least one Multi Sensor in the bus detects occupancy.
Daisy Chaining Multi & Wall Sensor
When Daisy Chained
- Not more than a wall sensor can be daisy chained in the bus, due to the absence of an address setting mechanism.
- The Temperature and Humidity values of the sensors in the bus are averaged for the master device