System characteristics
In the following sections, the characteristics of the system are described for the specific target.
A basic knowledge of the system architecture, installation options and equipment is required for a better understanding of the detailed design.
Basic design
PRF/PRA is a wireless control system that doesn’t require any additional wiring. PRA offers cloud connectivity using gateways to connect the wireless system devices to the services in the cloud. Because of its wireless design, the system is as easily to install in existing lighting infrastructures as well as new buildings.
New lighting systems based on LED technology enable significant energy savings, where PRF/PRA even can achieve additional savings, as the system is easy to control and highly flexible by means of apps on smart devices.
PRA offers connected benefits as well:
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For the installer and service provider, health status reports are available enabling efficient support to owners of the system (customers).
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for the Owner, insights about the operation of the lighting installation, showing current energy consumption, and remote control capabilities.
System architecture
It is useful to understand the high-level system architecture of both PRF/PRA - Foundation as depicted in High level system architecture of PRF/PRA - Foundation and PRA as depicted in High level system architecture of PRA
The combination of several hardware components and system specific firm- and software makes the PRF/PRA system.
The system consists of:
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Lights
Lamps or luminaires equipped with electronics to receive and send Zigbee messages. They form a mesh network that is very robust against failures or routing problems and exchange messages to execute control behavior. When a gateway is connected to the light network, the gateway is an integral part of the Zigbee mesh. It relays metric data to the cloud and enables remote control using the app or portal. Lights can come with built-in sensing capabilities or without.
PRF requires generation 2 lights that are Bluetooth-enabled. Generation 1 lights can be used for PRA only.
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Sensor
Device that senses presence of people in an area and triggers the switching of the lighting in the area by means of Zigbee. Daylight dependent regulation is possible with a multi-sensor that supports light sensing and occupancy detection. The system supports discrete Zigbee Green Power variants as well as sensors that are built into luminaires. -
Switch
Device that enables the possibility to control the lighting in an area manually, switch on or off, or dim up or down. 4-Button switches can also be used to assign scenes to. -
App
Software installed on a smart phone that is used for commissioning and operation. For PRA, the phone communicates via the cloud to the gateway and its lighting network. In Foundation, the app uses Bluetooth to connect to a light which will then relay messages to other lights using Bluetooth. -
Wireless Gateway
An edge device that connects the system to the cloud via the IT network of the customer and the internet. The wireless gateway connects with the lights by means of Zigbee. -
Cloud backend
Runs all the services and stores all the data for all systems worldwide. Data is organised on project basis with limited access for authorized users only. For PRF/PRA - Foundation, it backups security data needed to transfer access rights to other users and/or phones. -
Portal
A cloud-based webpage that can be used to access functionality of the system and to remotely control and monitor it.
System limitations
The table below describes the limitations of various characteristics of an PRF or PRA system.[1] Where applicable, a recommendation will given for applying a limitation to have optimal performance.
| Feature | Maximum number |
|---|---|
Project level |
|
Light networks (Foundation) / gateways (Advanced) |
20 |
Schedules |
16 |
Groups/schedule |
16 |
Owner accounts per project |
multiple |
User accounts per project (Advanced) |
multiple |
Light network level |
|
Lights (luminaires and/or Smart lamps) |
200 |
ZGP devices (switches and discrete sensors) |
50 |
Switches |
50 |
Discrete sensors |
30 |
Groups and zones |
64 |
Scenes |
128 |
Group level |
|
Lights (recommended)[2] |
40 |
ZGP devices |
5 |
Scenes |
16 |