The difference between instrument circuit numbers and instrument tag numbers
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This post was last edited by superme84 on 2021-6-23 00:41. HG20505 specifies the methods for numbering instrument circuits and instrument tags, but the lengthy format for instrument tags recommended in the standard, such as 10-TDAL-01A-1-A1, is not used in actual projects. Instead, instrument tags are more often denoted in the format PT-xxx, along with the DCS function identifier PICA-xxxx. What is the meaning of this numbering format, PICA-xxxx? Is it an instrument circuit number or a DCS function number? This is not clearly specified in the standards, so I hope someone can clarify it
This post was last edited by superme84 on 2021-6-23 00:48. As shown in FICA-011, what is its exact definition? What is the DCS regulator number? What is the difference from the instrument circuit number? Is the instrument circuit number shown in the PID diagram?
This post was last edited by myface on 2021-6-23 08:46. Learn about KKS coding – the identifier numbers are very long; cases like those in the example are indeed rare. Instrument circuit number
This representation contains control logic.
The instrument circuit number, as the name implies, is the circuit identifier; the old standard used to call it the system tag. An instrument tag, as the name implies, is an instrument number. The instrument circuit number is a designation assigned to a system, and this number should reflect the associated variables and functional requirements. An instrument loop consists of multiple instruments (physical and virtual instruments), and each instrument must have a number, which is known as the instrument tag. In 10-TDAL-01A-1-A1: 10 is a prefix that can be added as needed, or it can be omitted ； TDAL: TD stands for temperature difference, where T is temperature and D is a modifier indicating the difference ； AL low limit alarm, A alarm; L is a modifier indicating low ； Code 01A: 01 is the basic code, and A is a suffix (which can be added as needed) ； -1-A1 is a suffix that is added when necessary; it is optional.
Thank you for clarifying; in other words, the PICA-xx notation is also a instrument tag, but it refers to a virtual instrument in the DCS. May I ask again what the components of the current instrument construction drawings are, and where instrument circuit numbers are used? After checking the relevant specifications, it seems that in the current instrument indexes only instrument tag numbers are used; instrument circuit numbers do not appear to have any purpose
FICA-xx is the instrument circuit number, indicating that this is a flow indication, control, and alarm system with temperature and pressure compensation. Apart from that, everything else are the instruments that make up this system (physical and virtual instruments, or the various functional units that constitute the system).