Brief History of SCADA

SCADA (supervisory control and data acquisition) has been around as long as there have been control systems. The first ‘SCADA’ systems utilized data acquisition by means of panels of meters, lights and strip chart recorders. The operator manually operating various control knobs exercised supervisory control. These devices were and still are used to do supervisory control and data acquisition on plants, factories and power generating facilities

The sensor to panel type of SCADA system has the following advantages:
• It is simple, no CPUs, RAM, ROM or software programming needed
• The sensors are connected directly to the meters, switches and lights on the panel
• It could be (in most circumstances) easy and cheap to add a simple device like a switch or indicator

The disadvantages of a direct panel to sensor system are:
• The amount of wire becomes unmanageable after the installation of hundreds of sensors
• The quantity and type of data are minimal and rudimentary
• Installation of additional sensors becomes progressively harder as the system grows
• Re-configuration of the system becomes extremely difficult
• Simulation using real data is not possible
• Storage of data is minimal and difficult to manage
• No off site monitoring of data or alarms
• Someone has to watch the dials and meters 24 hours a day