Viconics VT7682S Application Guide - Manual (Page 9)

8
Basic Initial Design and Deployment Consideration
IMPORTANT: It is HIGHLY recommended that you do a proper field survey with the Viconics survey tools to establish
connectivity limitations and architecture layout on ALL job sites considered for deployment with the Viconics wireless
controller products. Please refer to the following manual for the survey procedures and tool usage: MAN VWG-
SURVEY-Exx.
Please note that the following is well covered in the field survey tool procedure manual. A quick summary is provided
here as a reference.
The Viconics wireless survey tools are intended to verify and validate the deployment and use of the Viconics wireless
controllers on a potential job site.
The survey tool will display a numerical percentage value on the LCD screen which represents the wireless network
Zigbee
™™ RSSI dBi value (Receiving Signal Strength Indicator).
 Any value from 10 to 100% indicates good Zigbee connectivity.
 Any value below 10% “may” indicate that an extra Router VRP 5000W1000W may need to be installed.
1.9. Knowing and understanding the 6A / 5H rule of Zigbee and how to cover orphan nodes
Zigbee is a standard which is suitable for wireless sensor and controller networks. In Zigbee, a device / node /
controller is said to join a network if it can obtain a Zigbee network address from a parent device. This Zigbee address
is a value which is NOT initially exposed or available for the integrator to see.
Devices / nodes / controllers can calculate and assign addresses for their surrounding devices by a distributed address
assignment scheme. This assignment is flexible, but it does somewhat restricts the number of attached devices and the
possible depth of the said network for any given device on the network.
Zigbee supports three kinds of networks type: star, tree, and mesh networks. The Zigbee coordinator ( In our case, this
is the Wireless Central Manager with the wireless communication card ) is responsible for initializing, maintaining, and
controlling the network.

A star network has a coordinator with devices directly connecting to the coordinator.

A tree and mesh networks, devices can communicate with each other in a multi-hop fashion.
The network is formed by one Zigbee coordinator and multiple Zigbee routers. A device can join a network as an end
device by the associating with the coordinator or a router.
A Zigbee device / node / controller is said to have successfully joined a network if it can obtain a Zigbee network
address from the main Wireless Central Manager coordinator or any other router devices / nodes / controller.
1.10. 6A stands for a maximum 6 addresses per device / node / controller.
Any given device / node / controller including the Wireless Central Manager –coordinator can ONLY give a maximum 6
Zigbee addresses out to other devices so they join the active Zigbee network. This means for any device / node /
controller to be able to successfully join a Zigbee network, it needs an address to be assigned by another device / node
/ controller which is within connectivity and that has NOT already assigned its maximum of 6 addresses allowed.
Please note that once a device / node / controller has been assigned a Zigbee address & has joined the active Zigbee
network, it will save its assigned Zigbee address to flash memory & re-use it afterwards even after a power failure or a
network re-start. The ONLY time device / node / controller would require a NEW Zigbee address is if the network is re-
started with either a new PAN ID or a new Channel value. This causes the currently assigned & saved Zigbee address
in flash to be erased & will force the / node / controller to try to re-join a new network.