The SICON is a control and evaluation unit by Sigrist-Photometer that serves as the human-machine interface for Sigrist process photometers and water quality sensors. It takes the raw measurement signals from turbidity, color, oil-in-water, or dissolved organic carbon sensors and presents them as calibrated readings on a color touchscreen — while simultaneously outputting 4–20 mA signals to the plant control system and logging historical data to an SD card.

How does the SICON connect to plant control systems?

Four galvanically isolated 0/4–20 mA analog outputs transmit measured values to PLC or DCS inputs. On the digital side, Ethernet with Modbus TCP is standard, and up to two optional interface modules can be added: Profibus DP, Modbus RTU, Profinet IO, additional 4–20 mA outputs, or 4–20 mA inputs for external sensors. Seven configurable digital outputs handle alarm annunciation, and five digital inputs accept external triggers such as flow switches or cleaning-in-place initiation signals.