Discrete controllers Industrial control system

panel mounted controllers integral hard displays. process value (pv), , setvalue (sv) or setpoint on same scale easy comparison. controller output co shown mv (manipulated variable) range 0-100%



a control loop using discrete controller. field signals process variable (pv) sensor, , control output valve (the final control equipment - fce). valve positioner ensures correct valve operation.

the simplest control systems based around small discrete controllers single control loop each. these panel mounted allows direct viewing of front panel , provides means of manual intervention operator, either manually control process or change control setpoints. these pneumatic controllers, few of still in use, electronic.

quite complex systems can created networks of these controllers communicating using industry standard protocols, allow use of local or remote scada operator interfaces, , enable cascading , interlocking of controllers. however, number of control loops increase system design there point use of plc or dcs system more cost-effective.