Can the following letter I be used for the display of digital values?
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As the title suggests, the subsequent letter ‘I’ in the instrument tag is specified to mean ‘indicator’. Can it be used for the display of digital signals? For example, for the high and low level switches on-site, whose signals are fed into the DCS for alarm display, can they be represented by the tag name LIA-XXX in the PID diagram?
Sure. LIA-XXX indicates level indication and alarm for XXX.
This post was last edited by 80372571 on 2022-1-26 at 15:13. It’s fine to use numeric labels followed by H or L to indicate the upper and lower limits.
According to HG/T 20505-2014, the initial letter D denotes density, and the letter D is used as a modifier to indicate difference. There is no rule specifying that digital quantities be represented by the letter D; neither in standard specifications nor in industry practices is this practice used.
Digital quantities are indicated by S interlock or A alarm; the indication for I is a numerical value, while digital quantities represent a status.