Process Indicators & Control Units

Process Indicators & Control Units

Process indicators and control units provide local indication and basic evaluation of measurement signals where a clear on-site view is required. Process indicators can indicate, evaluate, and calculate analog measured values, supported by large displays for readability across ambient conditions. Universal inputs allow connection of current, voltage, RTDs, and thermocouples, while loop-powered indicators require no auxiliary supply and can be used directly in 4…20 mA circuits, including intrinsically safe applications. Fieldbus indicators display values communicated on the bus.

The portfolio spans panel-mount and field-mount indicators, loop-powered indicators intended for direct installation in Ex areas, and HART-capable indicators that can display up to four values in a single device. For more advanced on-site functionality, variants add control features such as limit value monitoring, mathematical functions, differential pressure handling, and linearization. Fieldbus indicators complement these offerings by enabling straightforward integration into PROFIBUS PA and FOUNDATION Fieldbus environments.

Operating principles are tailored to the signal environment. Loop-powered indicators sit transparently in a 4…20 mA loop and are often selected when the transmitter display is hard to read due to installation constraints, while maintaining intrinsically safe suitability. Fieldbus indicators act as listeners that present bus values locally; PROFIBUS PA versions operate as pure listeners without their own device address, and FOUNDATION Fieldbus versions can operate in listener mode or via function block connections. Indicators with control function can combine roles such as active barrier, transmitter, and relay-based control into a single device to consolidate hardware.

Benefits include a strong price/performance ratio, fast commissioning, and additional security from local measured-value display. International approvals are available (including Ex, marine, SIL, and WHG) and the devices are designed for comfortable integration into bus systems. Typical applications include local indication at remote panels and skids, limit alarming and simple interlocking at the edge of a unit operation, and fieldbus segments where a local listener display improves situational awareness without adding control-system I/O.

Miller Mechanical Specialties, an exclusive authorized representative of sales and service for Endress+Hauser.