Given a system consisting of automatic production or process the operational side and the control or controller is required to provide it with some kind of mechanism that allows operator interaction with it. This type of system is called a generic human machine interface (HMI) and supervisory system and exploitation. There are several types of instruments to implement these monitoring systems (see Figure 5.1), which are studied later.
Keypads
Before the development of electronic technology and the popularization of PCs, this monitoring system was implemented by means of panels formed by push buttons and lamps and knobs and mainly 7-segment displays. The buttons allow the operator to the operating instructions of the automated system, such as start or stop working. The operator of the lamps through watching if some parts of the automation were operating or not. Turn potentiometers allow the operator to fix references in operation or numeric values as references to be achieved by regulatory systems of continuous processes. The displays were the natural way through the automated system which the operator moved operating margins of these continuous control loops.
This type of monitoring panels provided a very poor interfacial ce regarding alarm conditions that were simply marked by beeps and flashing lights, and of course did not provide any mechanism to record the values automated system evolution far from further analysis.
Figure 5.1: Tools for Monitoring and Auto Systems Operation and nuanced ¬
Operator Panels
With the development and cheaper systems based on microprocessors develop a form programmable instruments called "carrier panel" that allowed to perform all operations were carried out with the old handsets, but with a greater level of flexibility as are programmable and can be reused or modified easily by varying process conditions. See Figure 5.2.
Figure 5.2: Membrane Operator Panels
There are many different types of panels depending on the performance and price. The most basic present the user with two or three lines of text messages that can represent the conditions of the process of evolution. The most expensive present LCD or liquid crystal several inches in black and white or full color, allowing present the user with graphics depicting the evolution of the monitored process.
All these panels have a set of buttons that form a membrane keyboard that allows the operator to enter operating slogans or command ¬ ment activation and / or deactivation of various automated tasks. Some of these buttons can be associated with graphical icons represented on the screen, which allows high power use, by allowing an abstract way associated with the press of one of these buttons with the drive or not the component of the process represented by this icon .
In the more advanced and therefore more expensive, the buttons are replaced by a touch screen as shown in Figure 5.3. So the buttons are represented by a graph on the screen so that when the user presses with his finger the area of the screen where the button is represented will be carrying out the action of pressing the button.
Figure 5.3: Operator Touch Panels
Figure 5.4: Screenshot of a SCADA
