Process Indicators & Control Units

Process Indicators & Control Units

Process indicators and control units provide local indication and on-site evaluation of measured values, bridging the gap between field instruments and control/maintenance needs. Endress+Hauser notes that process indicators can indicate, evaluate, and calculate analog measured values, using large displays for readability under varying ambient conditions. Universal inputs support current, voltage, RTDs, and thermocouples, while loop-powered indicators require no external power supply and can be applied in intrinsically safe installations; fieldbus indicators display values communicated on the bus.

This category spans simple indication through integrated control. The portfolio includes panel- and field-mounted indicators, loop-powered indicators for direct installation in Ex areas, HART-display units that can show up to four values in one device, and indicators with control functions such as limit monitoring, mathematics, differential pressure, and linearization. Fieldbus indicators support integration into fieldbus systems for local visibility without disturbing the bus architecture.

Control-unit variants consolidate multiple functions in one footprint and can improve on-site responsiveness. Endress+Hauser highlights benefits such as fast, comfortable commissioning, added security through local measured-value display, and availability of international approvals (including Ex, marine, SIL, and WHG) depending on model and application context.

Typical applications include providing readable local indication where transmitter displays are inaccessible, adding alarm relays for local interlocks, supporting pump/valve control logic at the edge, and improving troubleshooting by showing live values during calibration, loop checks, and startup. Fieldbus indicators are useful for local readout without adding a separate analog loop.

Design considerations include input compatibility and scaling, display placement and enclosure rating, relay logic and fail-safe behavior, intrinsic safety requirements, and ensuring that added local functions do not conflict with existing control strategies. Standardization on a small set of indicator/control unit architectures can simplify spares, training, and maintenance documentation across the site.

At Eastern Controls, We are proud to be the exclusive authorized sales and service representative for Endress+Hauser.