Flow monitoring, for connecting Ex flow sensors of the FCS/FCI (NAEX) series, IO-Link device with relay outputs, operating voltage 20,250 VAC / 20,125 VDC, for Ex ia or Ex ib sensors, relay output for flow, temperature and error, switching point setting without teaching the flow limits (QuickTeach), LED strip for displaying flow velocity and media temperature, monitoring of the working and display range, wire break and short circuit detection on the sensor side, operation optionally in standard IO or IO-Link mode, parameterization via touch button and software-supported via IO-Link, associated equipment [Ex ia Ga / Da], connection of flow probes zone 0 / 20