How to Reduce Costs and Time for Wireless Hart in Industrial Networks
A process plant network is fairly complex, as different applications, such as visualization, asset management, and data historians require access to measurement and control data from the field. WirelessHart facilitates flexible integration of diagnostics data using a WirelessHart adapter — or from process measurements via WirelessHart instruments. A WirelessHart gateway is used to simply establish a connection to the network.
In the simplest case, the WirelessHart gateway is directly connected to the control system (Fig. 2). In this case, the wireless standard represents an alternative to the 4-20 mA wiring to transfer the process variables from the field instruments. The simplicity of the system is derived from the interface between the control system and the gateway, for instance, Modbus or Profibus.
The Hart commands are mapped to the I/O register format of the interface protocol. The control system can then use the measured data for simple closed loop functions or various calculations.
Alternatively, the user can connect the WirelessHart gateway directly to the control network level (Fig. 2), allowing the distributed control system (DCS) to directly accesses the gateway data. To achieve this, a commonly used communication protocol is used, such as Modbus. By integrating the WirelessHart gateway directly into the control network, additional controls are not required at the lower levels and new measurement points can be set up faster.