What is operator interface for SCADA systems?
Operator interface for SCADA systems provide the functions of status indication, alarm reporting, control action, data storage and programming.
What does HMI stand for in SCADA?
Operator interface or human-machine interface (HMI) for SCADA systems provide the functions of status indication, alarm reporting, operator intervention in control action, and data storage and programming.
How does a SCADA system work?
The operator interfaces which enable monitoring and the issuing of process commands, like controller set point changes, are handled through the SCADA computer system. The subordinated operations, e.g. the real-time control logic or controller calculations, are performed by networked modules connected to the field
What is Supervisory Control & Data Acquisition (SCADA)?
Supervisory control and data acquisitionSCADA) is a architecture comprising , networked data communications and graphical user interfaces high-level supervision of machines and processes. It also covers sensors and other devices, such as programmable logic controllers, which interface with process plant or machinery.
Operator Interface
Several levels or layers of operator interfaces are required to provide a reliable and maintainable system: equipment level, controller level, and supervisory level. At the controller and supervisory level, HMImay also provide the capability to modify the controller program. Note:The below-discussed points may vary from industry to industry. Consid
Equipment Level
Equipment level HMI should consist of a minimum of the control switches and indicators necessary to permit an operator to manually control the equipment in the absence of communications from the controller or for maintenance purposes. Examples of this level of control are hand-auto-off switchesand indicator lights at motor starters; local-remote sw
Controller Level HMI
At the controller level, the primary HMI device should be a graphical display/keypad combination providing access to input and output data, timer and register settings, and alarm and status screens. These devices are commonly panel-mounted in the door of the PLC cabinetand are available in enclosures suitable for hostile environments. With password
Supervisory Level HMI
Supervisory level HMI devices are typically personal computer workstations located in the central control room and/or management and engineering offices. The quantity and function of these workstations depend on the size and complexity of the industrial facility. Simple industrial facilities may be provided with a single workstation, which may be l
Human Factors
The design of HMI for SCADA systems must include consideration of Human Factors Engineering(HFE). It is estimated that 50 percent or more of all loss of load events in mission-critical industrial facilities involve human action. A commonly reported scenario begins with a single component failure and correct response by the automatic control system
Color Schemes in Scada
Color schemes used for controls and for graphic screensmay duplicate color codings used within the process, such as piping color codes or system color codes, or maybe developed strictly for the HMI. In all cases, colors should be selected to provide high levels of contrast without eye fatigue. Some rules for the use of color in HMI displays are giv
Select-Before-Operate
HMI softwareshould be programmed such that an operator must select the device to be controlled by point-and-click or other means and then select the operation to be performed. This two-step requirement for manual control can reduce errors resulting from the selection of the incorrect device. The selection of a device to be controlled should result
