Distributed control system having central control providing operating power to wireless transceiver connected to industrial process control field device which providing redundant wireless access

摘要

An apparatus provides redundant wireless to access field devices in a distributed control system having primary access to the field devices provided by hard-wired media that couples the field devices to the control room. The field devices are coupled to a Fieldbus control network. In a first embodiment, each field device is provided with a wireless Fieldbus port that is accessible by a wireless terminal. In a second embodiment, each Fieldbus control network is provided with a field module having a wireless Fieldbus port that allows all devices connected to the Fieldbus control network to be accessed by a wireless terminal. In a third embodiment, an H2-to-H1 Fieldbus bridge (which may service a plurality of H1 control networks) is provided with a wireless Fieldbus port that allows all Fieldbus devices connected to H1 control networks serviced by the H2-to-H1 bridge to be accessed by a wireless handheld unit of a wireless terminal. The redundant wireless access provided by the present invention allows a control room operator to access field devices in the event of failure or unavailability of the hard-wired media that provides primary access to the field devices.