This article will discuss some of the DCS DeltaV system architecture. DeltaV is DCS that a lot of applied in Oil and Gas Industry.
- 1 Workstation = 1 Node
- 1 Simplex = 1 Node Controller
- 1 Redundant pairs = 1 Node Controller
Total number of Nodes that can be installed = 120 Nodes.
Device Signal Tag (DST)
Tag Device represents a physical addressing instrument, valve and other instrument devices. Devices containing whereas DST tags and other special signals which is sourced from other equipment in the field (such as registers PLC, Profibus DO, AS Interface I/O, etc.).
DST in principle should be referenced by the Function Block, or in other words, the value has to be read by the function block.
DST is calculated on the basis of the following ways:
• An input from the system I/O that read by the Function Block (AI or DI) is called DST.
• An input signal to function block that referenced by other blocks in a different module is called as DST.
• Each output from the Function Block to System I / O (DO or AO) is called DST.
• Any input that appears on the graph, but could not read by function block is NOT called as DST. It is called as SCADA Value.
SCADA Tag is any I/O tag, the registers directly shown on the Operator Interfaces, for example:
• A discrete sensors are included in the DeltaV via a DI Card and shown directly on the Operator Interface.
• The values entered by OPCs shown in the Operator Interface.
SCADA tags can be shown to an operator, including a trend, written by the OPC, Operator Interfaces, look at the Operator Interface and tracked in DeltaV history.