Hello fellow PLC professionals! As we all know, electrical control system diagrams play a crucial role in the design and implementation of automated systems. These diagrams are used to convey information about the different components and their connections within a system, making it easier for technicians to troubleshoot and maintain the system. In this article, we will delve into the basics of graphics and text symbols used in electrical control system diagrams.
Firstly, let's define what graphics and text symbols are. Graphics symbols are graphical representations of electrical and electronic components, while text symbols are used to label and provide specific information about these components. These symbols are standardized and universally accepted, making it easier for technicians to understand and interpret the diagrams regardless of their geographical location.
One of the most common graphics symbols used in electrical control system diagrams is the rectangle. This symbol represents the PLC itself. Inside the rectangle, various symbols such as circles, triangles, and squares are used to depict different types of inputs, outputs, and memory elements. By understanding these symbols, technicians can easily identify the type and function of each component in the PLC.
Another essential graphic symbol is the line. Lines are used to represent the wiring or connections between different components. Different types of lines are used to convey specific information, such as power supply lines, inputs, and outputs. For instance, a solid line is used to represent the power supply, a dashed line represents a connection to a switch, and a dotted line represents a connection to a sensor. Familiarizing oneself with these symbols can significantly help in troubleshooting and system maintenance.
Now, let's move on to text symbols. These symbols are used to label and provide information about the components in the diagram. The most commonly used text symbols are numbers and letters. These are used to identify individual components and their connections. For example, an input device may be labeled as I1, while an output device may be labeled as Q1. These labels make it easier for technicians to identify and locate the specific component they need to work on.
Aside from numbers and letters, there are also other text symbols that provide important information about a component. For instance, a symbol with a line on top of a letter indicates that it is a normally closed (NC) contact. On the other hand, a symbol with a line underneath a letter indicates that it is a normally open (NO) contact. These symbols are crucial in understanding the functionality of the components within a system.
In addition to these basic symbols, there are also more complex graphics and text symbols used in electrical control system diagrams. These include timers, counters, and function blocks. Timers are used to control the duration of an action, while counters keep track of the number of times an action has occurred. Function blocks, on the other hand, are used to perform specific functions within the PLC. Familiarizing oneself with these symbols is essential in understanding the more complex diagrams used in industrial automation.
It is worth mentioning that while graphics and text symbols are standardized, there may be slight variations in their representations depending on the country or industry. It is crucial for technicians to refer to the specific symbol library used by their company or client to avoid any confusion or misinterpretation.
In conclusion, graphics and text symbols are the basic building blocks of electrical control system diagrams. By understanding these symbols, technicians can easily interpret and navigate through complex diagrams, making it easier to troubleshoot and maintain automated systems. I hope this article has provided you with the necessary knowledge and appreciation for these important symbols. Happy diagramming, fellow PLC professionals!