Help, what does it mean when the gauge is represented by a circle with a frame?
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What does it mean when a gauge is represented by a circle with a frame? What does a circle alone mean, without a square frame? What’s the point of having a frame? What do shared display and shared control panels mean? Which friend can explain it? Thank you
1. A circle without a box represents a single instrument or function; its fundamental meaning is an actual instrument (used to perform a certain function). 2. The circle with a box indicates the (virtual instrument) function in the Basic Process Control System (BPCS). In HG/T 20505-2000, the circle with a box is defined as the (virtual instrument) function in DCS systems. Since virtually all modern process control systems use DCS, the circles with boxes represent the functions within the DCS, that is, the virtual instruments (or modules) in the DCS. 3. By “sharing” is meant reusable modules (or virtual instruments) within a basic process control system, such as virtual PID controllers, virtual alarms, and virtual indicators.
Thank you, friend； So, for instruments with boxes around them: for example, pressure gauges – does the box surrounding the circle indicate that the instrument has a remote transmission function?
The pressure gauge is a physical instrument; it cannot have a box around it； If a pressure gauge with remote transmission is used, the box should not be included at night; however, if the signal it sends is displayed in the DCS, then the DCS display function must have a box. That is: a pressure gauge with remote transmission is represented by a circle without a box; the code for such a gauge is PIT, where the letter T in PIT indicates signal transmission (remote transmission), and the signal is transmitted to the DCS via dotted lines (representing electrical signals). In the DCS, the indication function is represented by a circle with a box, and the code for such a gauge is PI.
Boxed with a horizontal solid line inside the boxed circle: In the legend, there are three types – without a line, with a thin solid line, and with a dashed line. A circle surrounded by a box with a thin solid line inside indicates that the function is implemented and visible in the central control room; for example, indicators and alarms are implemented in the central control room； The dashed line inside the circled area with a box indicates that this function is implemented in the central control room but is not visible; for example, the square root operation is carried out in the central control room but it is not shown (no need to display it). In addition, double solid lines and double dashed lines can also be used; the double lines indicate that it is to be implemented in an on-site chamber (such as a field analyzer chamber).
The symbols on the dashboard are usually used to inform or warn the driver about the status of certain vehicle functions. A circle with a frame may indicate a specific warning or instruction, while a single circle may represent general information or a hint. “\"Shared display\" and \"shared control\" generally refer to the ability of multiple users to view or control the same device or system.
Instrument signals to the DCS system