Solutions for the Global Metals Industry

Non-TMEIC System ArchitectureLevel 2ControlL2TouchScrTouchScr eeneen TouchScreenHMIViewerWorkStationControllerOtherControllersNew Control network3New EquipmentHMIBridgeControllerFiberOpticLinkFullControlNew I/OControllerFiberOpticLinkNo Control(SignalsMapping)New I/OControllerFiberOpticLink2DRVDRVDRVTMdrive®TMdriveTMdriveOld Equipment- System “S”PartialControlControllerNo Control(SignalsMapping)ControllerOld System NetworkFullControlController4Old I/ODRIVEA VOld I/ODRIVEDRIVEA VA VOld I/O1The modernization or replacement of an old control systemsupplied by another vendor presents an implementationchallenge. The replacement project has to minimize:• Additional shutdown periods• Post-switchover production disturbances• Installation complexity and costDue to incompatibility of old networks and components,the standard approach is to install a complete new system,remove the old one, and execute the switchover in one bigstep.Approach to Replacement of System “S”Item1234Page 26 of 40Equipment NotesEstablish Controller Connectivity- Install interface boards in the old controllers; (these may be two types, for example MultiBus I and II)- Install matching interface boards in the new controllers (VME rack) and establish the data exchange usingfast fiber optic links (with some other vendors’ systems, DECNET communication may be used for dataexchange)- Map the data to and from the old system to and from the new global control networkNew HMI System- The new HMIs and level 2 computers are easily implemented and are initially tested in passive mode, thenswitched to bidirectional data flow (with other vendors’ systems, the new level 2 computer acts as thecommunication gateway, both for HMI and level 1 control)Drive Modernization- The new drives are installed and connected to the new controller. In the initial stage, the new controller only actsas a drive bridge since the old controller is still in active operation- In some cases the old drives temporarily run with the new controller. In this case, the old controller justbidirectionally maps all drive and I/O signals to the new controller (with other vendors’ systems, some of the oldcontrollers and drives may be retained and kept active, and may communicate through the level 2 gateway to theHMIs)- By switching over small sections of I/O and associated functionality during brief shutdowns, no productionstoppages or interruptions are introduced© 2011 TMEIC Corporation. All Rights Reserved.This requires an extended shutdown period and introducessignificant risks because all system levels must be startedand tuned up at the same time. A way of minimizing risk isto connect all the new I/O in parallel with the existing I/O,but this is very costly due to the additional engineeringand installation materials and labor.TMEIC’s approach to these problems uses connectivityto the old system components and a step-by-step controltakeover. The figure above shows an intermediate stagein an implementation.