ZNM Technology Overview
The networking protocol in the ZNM modules is ZigBee® based on the Z-stack from Texas Instruments.
What is ZigBee®?
The ZigBee® protocol is an open RF standard operating on the 2.4 GHz frequency. ZigBee® is particularly useful for low-data rate, low-power, wireless communications for Machine-to-Machine (M2M) and Internet of Things (IoT) networks worldwide.
ZigBee® uses a mesh topology network architecture where each node relays data for the network and all mesh nodes cooperate in the distribution of data throughout the network.
In contrast to Wi-Fi networks — used to connect endpoints to high-speed networks — ZigBee® supports much lower data rates and leverages its mesh networking protocol to eliminate hub devices and create a self-healing architecture.
Radiocrafts ZNM modules use ZigBee® PRO. ZigBee® PRO aims to provide the foundation for the IoT with features to support low-cost, highly reliable networks for device-to-device RF communication.
Radiocrafts’s ZNM is a protocol based on the TI Z-stack (http://www.ti.com/tool/z-stack) that is fully ZigBee® compliant. The ZNM protocol creates a configurable overlay on the Z-stack, reducing the device manufacturer’s programming to a minimum while maintaining ZigBee® compliance.
ZigBee® Nodes & Their Functions
The ZigBee® protocol defines three types of nodes: coordinators, routers and end devices. Although all nodes can send and receive data, they each play a different role.
There is one coordinator in each network; its job is to store information about the network, including security keys. Routers are intermediate nodes, relaying data from other devices. End devices can talk to the coordinator or a router, but they can’t relay data from other devices. End devices are typically low-power and/or battery operated.
ZNM Data Rates & Wireless Range
ZNM has a defined data rate of 250 kbit/s, suitable for intermittent transmissions from a sensor or input device. Transmissions are secured by 128-bit symmetric encryption keys.
Due to its low-power, ZNM modules have limited transmission distances; ranges can vary from 10 to 100 meters line-of-sight, dependent on the environment and RF power output. Nevertheless, when used in a mesh network of intermediate devices, Radiocrafts ZNM modules can effectively transmit data over long distances.
ZNM Applications: Residential, Commercial, Industrial
Radiocrafts ZNM modules are ideal for residential, commercial and industrial equipment that requires short-range, low data rate wireless networking. Typical ZNM applications include:
- Wireless sensor networks (WSNs)
- Industrial control
- Building automation and retrofits
- Smart homes, including automated lighting and shutters/blinds, HVAC systems, smoke and burglar alarms
- Medical data collection and monitoring
A full description of how to configure a Radiocrafts ZNM module can be found at our document library.