Before the modernization the operating mode control system of a sizing mill was implemented on basis of ControlLogix 5550 controller (Allen Bradley). Data exchange between ControlLogix controller, 1336 PLUS II frequency converters (Allen Bradley), ACS880 frequency converter on the 7th mill stand (ABB) and PV1000 operator panel (Allen Bradley) was executed via ControlNet network. The frequency converter was managed by ControlLogix 5550 controller using analog and discrete signals.
After the modernization.
Since the interface capabilities of the existing 1336 PLUS II frequency converters do not allow of exchanging the necessary data with S7-1515 PLC, they stay connected to the ControlNet network. ControlLogix 5550 PLC remains and functions only as a master of ControlNet network; it translates the data received from 1336 PLUS II frequency converter to S7-1515 PLC and also transmits the commands and parameters from S7-1515 PLC via ControlNet network to 1336 PLUS II frequency converter.
The newly installed operating mode control system of a sizing mill is implemented on basis of Simatic S7-1515 PLC by Siemens. Instead of PanelView 1000 operator panel, connected to ControlLogix 5550 PLC, the mill control desk is equipped with TP1200 Comfort operator panel (Siemens), connected to Simatic S7-1515 PLC. Data exchange between Simatic S7-1515 and TP1200 is executed via Profinet network.
The new Inovance MD 880 frequency converter with HPFN-10 network module is installed for a drive of the 1st mill stand. The new frequency converter is managed by S7-1515 controller using analog and discrete signals. For this purpose the analog and discrete output modules are installed inside the S7-1515 controller. Later on, after step-by-step replacement of the existing frequency converters, these modules can be used as sources of control signals for new frequency converters. The S7-1515 controller receives from a new frequency converter via Profinet network the signals, essential for generating an analog speed setting, diagnosing the frequency converter status and visualizing on the operator panel.
For data exchange between ControlNet and Profinet networks the Anybus network bridge is used, which is a slave device in both networks. At a later stage, in the course of piecemeal replacement of frequency converters for drives of the other mill stands, with possibility of connecting them to Profinet network of S7-1515 PLC and controlling the drives with the use of discrete and analog signals from S7-1515 PLC, the need for ControlNet network will cease to exist.