Communication system for controlling technical system, has field devices divided into local groups, and converters arranged in center of group of field devices, which are connected with central device over communication network

摘要

The system has field devices (11-13, 21-24) divided into local groups, and converters (31, 32) arranged in a center of the group of the field devices. The field devices are connected with a central device (50) over a communication network (60). A wireless communication connection shorter in range is provided between the field devices and the converters. Another wireless communication connection longer in range is provided between communication terminals (41, 42) e.g. personal digital assistant-minicomputer, and the converters.