[FUN] Anyone putting different DCS's in the same control house?

[Stephen Mitschke]

> Dear all,> > Given the struggles we have with our installed base of legacy DCS, I'm> curious how many are going so far as to have competing DCS's side-by-side> in> their control house? Or maybe, DCS's from the same vendor that aren't> interoperable?> > John Rezabek

[Stephen Mitschke]

> At Huntsman Tioxide's Greatham UK plant we are building a new pigment> production plant with Emerson's Delta V and FF instrumentation. The new> process plant is largely a copy of an existing plant which has ABB MOD300> DCS and classic field instruments. Both systems are about 1500 I/O. Each> plant has its own control room but they are in the same control building.> There will be some exchange of operations and maintenance staff between> the> plants. In time we plan to migrate the older plant to Delta V, but for> some> time the site will have different systems from different vendors.> > Cheers> > Gary

[Stephen Mitschke]

> John,> > I work primarily with DeltaV and very often when we install our systems at> sites having legacy systems (usually various PLCs). Some customers do not> want to remove them for various reasons and we integrate these PLCs> in DeltaV either via DeltaV Serial Interface or via OPC link.> > Oleg Rojkovski

[Stephen Mitschke]

> Dou you have DeltaV interfaced with field bus? How is the performance?> > alex pachecoZuari, India

[Stephen Mitschke]

> Yokogawa has some experiences to integrate different DCS system and PLC> system> such as Yokogawa CENTUM/Micro-XL series, Honeywell TDCS series,> Foxboro IA series and Modbus system on Process Automation Information> level.> > We can provide a standard package with the communication driver.> The main interface is OPC.> > Attached files are sample documents.> (See attached file: pims_010713.pdf)(See attached file:> PIMS_DCS_Support010713.PDF)> > Best Regards,> Takehiro Ishikawa <<Adobe Portable Document>> <<Adobe Portable Document>>>

[Stephen Mitschke]

> We've got a large existing Provox installation that has decided to go> DeltaV> for all new projects. Operation will be from Provox stations via OPC for> the time being.Jim SpragueAramco

[Stephen Mitschke]

> As mentioned by many OPC is an excellent way of integrating systems. The> existing DCS can be fitted with an OPC server. Although the OPC server is> not "native" to the DCS there are third party suppliers that have> developed> OPC server for most DCS. These servers typically run on dedicated Windows> NT> computers fitted with the appropriate interface card. Many Fieldbus hosts> implement OPC servers as standard that can also be redundant in our case.> At> a plant upgrade the existing DCS consoles are usually replaced by Windows> NT> workstations running OPC client software. This allows the modern and> existing systems to be operated from the same "dashboard". OPC is ideal> for> bringing data to the operator screens. It is the best solution. Make sure> the OPC server for the Fieldbus host gives access to all data in function> blocks as well as transducer blocks. You want to access diagnostics etc.> from other applications, not just process I/O.> > Using an OPC bridge (a piece of software) a modern and a legacy system can> exchange data. This data exchange relies on the availability of the bridge> and server computers. If one "hangs" the link is lost.> > Another way to exchange some data between a modern Fieldbus system and an> existing DCS is through a Modbus communication network. Most DCS has> support> for Modbus. E.g. process I/O data from Fieldbus can get to and from the> central DCS controller this way. The Smar DFI302 linking device is also a> Modbus gateway supporting Modbus/RTU (integral serial port) and Modbus/TCP> (IP on Ethernet) and can act as a master or slave. I.e. acting as a serial> slave it can pass data to a DCS essentially acting as part of the> I/O-subsystem. Fieldbus data gets in and out of the DCS without passing> through any Windows. A process variable from a Fieldbus transmitter links> to> a multi I/O function block and becomes available as a Modbus register that> can be read from the DCS. The DCS writes outputs to another Modbus> register> and the value becomes available as a regular function block output that> can> be linked to a valve positioner or be used in the control strategy just> like> any Fieldbus value.> > It is unrealistic to map all Fieldbus data into the legacy DCS (OPC or> Modbus) since Fieldbus provides several hundred pieces of information per> field instruments. It would be too much work, error prone and may result> in> an overload of proprietary networks and databases. Therefore it is> required> to have a Fieldbus engineering and maintenance station for configuration> and> asset management for the Fieldbus instruments.> > In a Modbus master mode it can be used to get data from flow computers,> weighting scales and RTUs etc. making it available as regular Fieldbus> process variables> > Jonas> Smar