Nowadays the majority chemical, refined product, crude and pipelines of gas are managed from a central location using systems of Supervisory Control and Data Acquisition (SCADA). Usually system of pipeline SCADA s include two main components, they are a single host system and many field systems.
For host system, it means the software and hardware installed and running in the central facility control. SCADA host systems in the pipeline applications characteristically correspond with an amount of field systems installed at important locations alongside the pipeline such as, station pumping, breakout storage, station receiving, delivery point, etc. while field systems communicate frequently with the host system through a particular scheme of communication as required by the host software of SCADA.
The systems of field automation carry out detailed pipeline control, for instance ESD protection, valve interlocking, and other specific element of low-level functions for a the pipeline. Additionally to low-level control, field systems frequently include a GUI (graphical user interface) for personnel of operations and maintenance at the field site.
The default technology implemented within field systems has included PLCs and PC-based HMI software for many years. Field systems are normally built by engineers within the owner pipeline company or by engineers operating for independent system integration firms.
This compares an option to the traditional technology of PLC/HMI arranged for field automation along a pipeline. The other option presented is UCOS system of Control Systems International. Two options are analyzed:
• Change the existing equipment of automation with technology of PLC/HMI according to standards company or
• Change the existing equipment of automation with a UCOS system
One of the option need to chosen that they will be used the Wondwerware InTouch HMI software and General Electric 90/30 PLC for field automation projects. This solution will address the owner of pipeline corporate needs to provide new PLCs and new HMI PCs at every station. The available I/O modules have to be changed when the latest PLCs are assembled. For that reason, new modules of I/O will be installed in cabinets and pre-wired in a panel shop to let for re-termination at the available marshalling cabinets. This will decrease the amount of time needed to essentially install the new I/O and PLC. The stations of Wonderware and PLCs will be linked together through the interface network which already available at every station. The communications to the host of SCADA will continue to employ the Modbus protocol.