The ABB 2TLA020070R4600 is a Pluto B20 V2 safety PLC with 20 I/O points, communicating over the Pluto safety bus. It carries 8 failsafe inputs, 8 non-failsafe outputs that can also serve as failsafe inputs, plus 2 individually failsafe relay outputs and 2 individually failsafe transistor outputs. This is the current-production variant — no lifecycle concern for new designs or line spares.
I/O map and safety architecture
The 8 failsafe inputs handle safety-rated signals from e-stops, light curtains, or interlock switches. The 8 configurable channels let you trade output capacity for additional failsafe inputs if the application needs more than 8 safety inputs. The 2 relay outputs and 2 transistor outputs are individually failsafe, meaning each can be wired to a separate safety zone or actuator without shared fault paths.
Pluto safety bus integration
The Pluto safety bus is a deterministic, closed-loop protocol for daisy-chaining multiple Pluto units. Each node on the bus exchanges safety data (input states, output commands) within a single cycle, so you can distribute I/O across a machine without running individual cables back to one central controller. The bus itself is safety-rated — no separate safety relay per node.