Doc: ps2001-5-1101-001 Rev: R02. 00
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1486357009-URS, URS
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- 4.2.1 Supervisory systems
§ 4.2-(3), these will be either documented as a whole (i.e. all the modules that makeup the control process are explained in one document, or each module will be documented individually, but an additional document will be supplied explaining how the modules function together as a whole. 8 PID Control loops, are proportional-integral-differential or three term controllers these are an industry standard approach to maintaining a process value (pressure for example) at a particular target value (setpoint). PID control is widely used inmost process applications. 38-71 Doc PS Rev R (5) The standard modules will have a common and consistent approach to how data is passed to the modules for example, if data structures are used to pass data, all standard modules should do this in a similar way. (6) Consideration must be given to ensuring that configuration data fora module (for example, the fixed operating times fora particular valve) can be stored in such away that it is verifiable (that is to say that it can be checked against a copy of the software that is known to be accurate to verify that the installed data is the correct version. Such data must be distinguishable from transient “live” data (for example, the expired time of a valve operation whilst that operation is in progress, the current dynamic state of a valve c. (7) Where different modules have similar modes of operations (for example, switching a valve or a drive to manual mode, these modes must be implemented in a consistent manner (i.e. common use of variable names, data structures c. 4.2.1 Supervisory systems (1) The standard modules will be designed to interface to a supervisory system of some nature (typically, a SCADA 9 system or HMI 10 application). The modules will be designed with this functionality in mind and this interface will be documented as part of the module documentation, further information is given in § 4.9. (2) The supervisory system interface shall allow for graphical representation of the devices and instruments (open, close, running, stopped, in fault c these shall be standardised in approach, appearance and in terms of how the data will be passed to the supervisory system (all blocks should do it in the same way. A SCADA (supervisory control and data acquisition) system is a computer system used to gather and analyse real time data from the control system, it will display the status of the equipment (graphically showing if a valve is opened or closed, if a drive is running, instrument readings cit will show alarm and warnings and will allow the operator to issue commands to the control system (start a sequence, take manual control of a device c. 10 HMI (human machine interface) is generally a panel mounted computer-based system similar in functionality to a SCADA system, but generally more restricted in its facilities and functions. Doc PS Rev R 39-71 (3) The standard modules shall allow for alarm, warning and event messaged to be generated within the modules (e.g. device fault, high alarm, error warning, c) and for these messaged to be communicated with a supervisor system in a consistent fashion. (4) The standard modules shall allow for commands to be received from a supervisory system to select different operating modes, change functional options, modify specific parameters c again, such commands must be structured in a common and consistent manner across all modules. Note: The supervisory systems themselves do not form part of this project, and will not be developed as part of it (although it is envisaged that this development will take place in a future project) Download 1.5 Mb. Share with your friends:
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