Digital Panel Meters
Digital panel meters are devices that convert an input signal into a digitally displayed value. They are mounted in control panels where monitoring and control is taking place. Input signals are often measurements from sensors which are then converted and displayed as pressure, temperature or other system variables. Some digital panel readers can perform simple control functions when readings reach a preset measurement.
Digital panel meters have more options to consider other than basic display. Some provide data interface functionality that allows the user to interact with information that is displayed. Some allow users to preset input values that trigger alarms or control functions when reached or exceeded. Some meters provide an analog output proportional to the input signal for use in analog devices.
Analog panel meters still remain appropriate for some applications, however, they have largely been replace by digital panel meters, which are easier to read and far more accurate. Digital panel meters are used extensively in process control and electrical equipment. They are used to monitor voltage fluctuations in large industrial motors and can be used for sub-metering applications to track real-time power conditions and monitor equipment to increase network reliability and power availability.
Products
Human Machine Interface (HMI) is a software interface that allows operators to interact with various pieces of electrical hardware and controls systems. HMI typically utilizes monitors or screens to display information, which are referred to as HMI screens. The screens are not the actual HMI, but are a tool used to display HMI software. For example, electrical enclosures often have screens mounted on the outside of them to provide users with information about ongoing process and to allow users to make changes to the system.
Operator Interface Terminal (OIT) typically displays basic information about the electrical hardware that it is attached to. It provides only local information about the environment it is interfacing with and allows control and monitoring for that one piece of hardware, not an entire system.