What is SCADA?
SCADA stands for Supervisory Control and Data Acquisition. These systems were originally created in the 60's on mainframe and mini-computer systems. Today the typical implementation is PLC (programmable Logic Controller) controls and PC's usually connected to a PC Network for centralized data collection. There has been a huge boom in the number of software packages that provide this functionality.
Typical Components include:
- External access. This provides the machine connection. Physical media include serial communications (RS-232C), PC card access (AB DH+, ARCNET, Modbus Plus) or direct analog/digital I/O. Newer connections are fieldbuses, such as DeviceNet, Profibus or even Ethernet and USB
- Process Alarming for out of tolerance conditions.
- Data logging and reporting. Productivity and shift reports
- Operator interface. The operator screens are usually designed with an offline graphical editor.
- Computation engine. This allows the package to calculate totals, averages, SPC (Statistical Process Control) summary data and any derived information from the raw data.
- Network access. Usually packages allow remote viewing of the process from another station. This can be done using NETDDE or DCOM in Windows based packages.
- Database access. Many packages allow direct logging and retrieval of information from a centralised database server, such as Oracle, Sybase or Microsoft SQL Server. In general Windows based packages use ODBC or ADO access.
- Custom programming. Different packages allow different level of customisation. Some will supply C libraries, others provide custom tool sets and some just allow program triggers within the package to run another program.
Video about SCADA/DCS and network security