Manual override must be possible to shut down equipment and protective systems in automatic processes that drift from intended operating conditions, without compromising safety. On emergency shutdown, accumulated energy (other than electrochemically stored energy) must be dispersed or isolated as quickly and safely as possible. Where a power failure could spread additional risks, the product must be able to stay in a safe operating state independently of the rest of the installation. Suitable cable and conduit entries must be fitted and interfaces with other equipment must be safe, and where detection or alarm devices monitor explosive atmospheres the instructions must allow them to be placed at the right points.
The graph holds this control, the 0 it maps to, and the evidence behind each claim, over MCP and REST.