🔍 Key Concepts

• In an advisory control configuration, the computer provides advice or setpoints, but does not directly drive all actuators. • Look at how the Manual Input/MAN block is connected in Figure A: what devices or controllers does it feed, and where is it located relative to the operator console and engine room? • Distinguish between central consoles used to operate the whole plant and manual backups used when automatic/supervisory control is lost.

💭 Think About

• Does the MAN block appear to control one specific function (such as engine speed) or does it tie into the same path that the automatic controllers use for process control? • Is the MAN block part of the normal remote operating console, or is it drawn as an alternate route to the analog/digital controllers when the computer is bypassed? • In an advisory control system, if the computer fails, how would the crew still be able to adjust the process variables—through what kind of control mode?

✅ Before You Answer

• Trace the arrows: what signals go into MAN and what signals leave it toward the analog/digital controllers? • Ask whether MAN is labeled or positioned as a local console in the engine room, or as a functional mode of control in the loop. • Decide if MAN’s purpose is ongoing remote maneuvering, fine adjustment of parameters, or backup manual control of a control loop when automation is not available.