SCADA systems are used to monitor or to control industrial, physical, transport processes or telecommunication systems. The term refers to a large-scale, distributed Measurement (and control) system. It is a central system that monitors and controls a complete site. The bulk of the site control is usually performed automatically by a Programmable Logic Controller (PLC).
A SCADA control center performs centralized monitoring and control for field sites over long-distance communications networks, including monitoring alarms and processing status data. Based on information received from remote stations, automated or operator-driven supervisory commands can be pushed to remote station control devices, which are often referred to as field devices. Field devices control local operations such as opening and closing valves, starting of pumps, collecting data from sensor systems, and monitoring the local environment for abnormal operating conditions.
What is SCADA?
SCADA stands for Supervisory Control and Data Acquisition. Basically, SCADA is a system for gathering and analyzing real time data. As the name implies, it focuses on the supervisory level. It is also a software package that interfaces with hardware, via Programmable Logic Controllers (PLCs), or other commercial hardware modules like RTU’s (Remote Terminal Unit). Systems similar to SCADA i.e. DCS (distributed Control System) are routinely seen in factories, treatment plants etc. They have similar functions to SCADA systems, but the field data gathering or control units are usually located within a more confined area.
A SCADA System usually consists of the following subsystems:
- A Human Machine Interface or HMI which displays process data to a human operator. It also allows human operator monitor and control the process. The HMI is usually linked to the SCADA system’s databases, to provide trending, diagnostic data, and management information such as scheduled maintenance procedures, and detailed schematics. The HMI presents the information to the operating personnel graphically, in the form of diagrams. This means that the operator can see a schematic representation of the plant being controlled
- A supervisory system which acquires data on the process and send commands (control) to the process. An important part of most SCADA implementations is alarm monitoring. The system monitors whether certain alarm conditions are met, to determine when an alarm event has occurred. Once an alarm condition has been detected, one or more actions are taken (such as the activation of alarm indicators, and the generation of email or text messages so that management or remote SCADA operators are aware).
SCADA SYSTEM ACHITECHTURE
SCADA system Architecture is divided into two, which are Hardware Architecture and Software Architecture
The basic hardware of the SCADA system is distinguished into two basic layers:
The client layer which caters for the human machine interaction and the data server layer which handles most of the process data control activities. The data servers communicate with devices in the field through process controllers. Process controllers, e.g. PLC’s, are connected to the data servers either directly or via networks or fieldbuses that are proprietary, or non-proprietary (e.g. Profibus). Data servers are connected to each other and to client stations via an Ethernet LAN. Fig.1. shows typical hardware architecture.
GENERIC SCADA HARDWARE ARCHITECHTURE
SCADA are multi-tasking and are based upon a real-time database (RTDB) located in one or more servers. Servers are responsible for data acquisition and handling like polling controllers, alarm checking, calculations, logging and archiving) on a set of parameters, typically to which those are connected. However, it is possible to have dedicated servers for particular tasks, e.g. historian, data logger, alarm handler.
GENERIC SCADA SOFTWARE ARCHITECTURE
LIST OF PROJECT
Gil Automation as a Systems Integrator has executed several projects deploying SCADA System. Below is a list of some past and present projects:
- Itoki Fire Hydrant Project (CLIENT: WAPCO).
- PLC5 to Controllogix SIL2 ESD System Upgrade (CLIENT: CHEVRON)
- Meji Debottlenecking Upgrade project (CLIENT: CHEVRON)
- Propane Sphere Expansion project (CLIENT: NAVGAS).
- Meren Water Injection Platform project (CLIENT: CHEVRON)
The GIL Assurance
One of the most important measures we take at GIL Automations in delivering high quality, and safely operable systems ‘that work’, is to partner only with OEMs with global footprint and relevance, with high quality standards. We can always bank on their support to deliver according to global standards. Our Engineering teams are also second to none; as we pride ourselves in ensuring customer satisfaction. Our assemblies are rugged, designed to meet even the strictest of standards; both locally and on the global scene.
At GIL Automations, we pride ourselves at being the forefront of technology deployment and innovation; and as such, possess a world-class facility for the development of SCADA systems. In addition to SCADA system development, we also carry out general Automation/Control System design, installation and maintenance. Our clientele spans the upstream and downstream sector of the Oil & Gas Industry, Manufacturing, and Power/Energy Industries.
GIL Automations as a premier systems integrator, in partnership with many world-leading Original Equipment Manufacturers (OEM’s), remains committed to providing support to all our clients on the implementation of innovative systems that work.