Pepperl+Fuchs WirelessHART system components

Automated Control Engineering has introduced WirelessHART system components from Pepperl+Fuchs that integrate conventional field devices into the wireless world.

The system is based on the HART protocol, allowing easy integration into any existing fieldbus infrastructure and uses the 2.4 GHz band for several radio technologies.

A flat mesh network where all radio stations (field devices) form a network is at the heart of the system. Every participating station serves simultaneously as a signal source and a repeater.

The original transmitter sends a message to its nearest neighbour, which passes the message on until the message reaches the base station and the actual receiver.

Alternative routes are set up in the initialisation phase. If the message cannot be transmitted on a particular path, due to an obstacle or a defective receiver, the message is automatically passed to an alternative route.

So, in addition to extending the range of the network, the mesh network provides redundant communication routes to increase reliability.

The communication in the network is coordinated with TDMA (time division multiple access) that synchronises the network participants in 10 ms timeframes.

To avoid jamming, WirelessHART uses also FHSS (frequency hopping spread spectrum).