TS 2204

TS 2204 is a standard on analogue direct current signals used in process control systems for transmitting information between system elements. It addresses the common technical language of current-based signalling in industrial measurement and control, and it draws an important boundary between signals used for inter-element communication and signals used entirely within a single element.

Signal type and practical context

Direct current signals are widely used in process automation to carry variable process information between devices such as sensors, transducers, indicators, recorders and controllers. Current-based transmission is especially valued in industrial environments because it is practical over distance and generally well suited to electrically noisy installations. In general technical context, this makes analogue current signalling one of the foundational concepts in industrial process measurement and control.

What this standard covers

• Analogue direct current signals used in process control systems
• Information transfer between elements of a system
• Signals used in industrial-process measurement and control systems
• Signals used entirely within one element are outside the stated scope

This edition is the second edition and it replaces the first edition; it is based on IEC 381-1:1982 as an equivalent source. For users of automation and instrumentation documentation, TS 2204 is therefore best understood as a vocabulary and scope reference for analogue current signalling rather than a source of detailed circuit design rules, numerical ranges or implementation procedures.