September 9, 2007: The scope of this project consisted of the replacement of an array of Allen Bradley PLC2 PLC CPU’s controlling a kraft mill bale line with a single Allen Bradley ControlLogix PLC. The CPU in each existing PLC2 was replaced with a 1771-ASB module to allow communication from the ControlLogix PLC to the existing I/O in each PLC2 chassis with Remote I/O (RIO). As a result there was no new I/O wiring required to complete the conversion, the software for all existing PLC2 PLC’s was converted and merged into the ControlLogix CPU and only the existing PLC2 to PLC2 interlock I/O wiring which was replaced by equivalent software interlocking was required to be disconnected.
A new Allen Bradley RSView HMI operating on a standard desktop PC replaced the existing “Bale Scale Computer” PC. The functionality, including communication to the infeed bale scale and digital display, the outfeed bale scale and digital display, the bale counter digital display and the stenciller, of the existing OEM Bale Scale Computer was integrated into the new ControlLogix PLC along with The RSView HMI. The ControlLogix PLC echoes information to the RSView HMI which archives and displays data as well as allows operator input. The system has the capacity, by Ethernet, to communicate to the mill process computer for information gathering and display, as well as for remote monitoring the ControlLogix PLC and RSView HMI as applicable.