Electrical signal line symbol
Also called Electronic signal
An electrical signal line carries an electronic signal, such as 4 to 20 mA, between instruments and the control system.
What the electrical signal line symbol means
An electrical signal line carries an electronic signal, such as 4 to 20 mA, between instruments and the control system.
How it is drawn
A thin dashed line.
The electrical signal line symbol in each standard
Drawn as ISA 5.1 defines it, as on most US and international legends.
Signal lines are not part of ISO 10628-2. They come from IEC 62424 or ISA 5.1.
German (DIN): Elektrische Signalleitung. See DIN P&ID symbols.
Where you see it on a P&ID
Between transmitters, controllers, the DCS and electrically operated devices.
Tag codes
The electrical signal line is commonly tagged:
- ISA 5.1
Tag formats follow the project numbering procedure. For instruments, the letters follow ISA 5.1, explained on the instrument symbols page.
Related symbols
Frequently asked questions
What does the electrical signal line symbol look like on a P&ID?
A thin dashed line.
What is a electrical signal line used for?
An electrical signal line carries an electronic signal, such as 4 to 20 mA, between instruments and the control system. Between transmitters, controllers, the DCS and electrically operated devices.
What tag does a electrical signal line have?
It is commonly tagged ISA 5.1. The exact tag format comes from the project numbering procedure and the legend sheets.
Is the electrical signal line symbol the same in ISA and ISO?
Signal lines are not part of ISO 10628-2. They come from IEC 62424 or ISA 5.1. Companies vary the details, so always check the legend sheets at the front of the P&ID set.
What is the electrical signal line called in German?
Elektrische Signalleitung. On a German R&I-Fließschema it is drawn to DIN EN ISO 10628-2.
- In production since 2014
- Thousands of daily users
- On MODEC FPSO projects since 2016