Yokogawa ALF111-S51 Fieldbus Communications Module

The Yokogawa ALF111-S51 Fieldbus Communication Module delivers FOUNDATION Fieldbus H1 connectivity between controllers and field devices in CENTUM DCS node units, acting as a Link Active Scheduler (LAS) to coordinate timing and data exchange across fieldbus segments. It provides four ports (one segment per port) at 31.25 kbps and supports up to 32 devices per segment with up to 48 I/O points, making it suitable for connecting field instruments such as transmitters and valve positioners in industrial process control environments like oil & gas, chemical plants, power generation, and manufacturing systems. It is designed for installation on Yokogawa node units such as ANB10/ANB11, AFV, and A2FV series, with a field-to-system withstand voltage of 1500 VAC and an approximate weight of 0.4 kg. Common replacement: AIP502.