Standard Master Unit. 8 Inputs. 2 OSSD pairs (SIL 3). Screw Terminal Blocks Master Unit for the control of any other expansion unit (not compatible with: MI8O4, MO4L and MA4), can also work as Stand-Alone As Master Unit: to control a more complex system providing protection for bigger machineries with multiple sensors As Stand-Alone: to control smaller machinery connecting with up to 4 safety devices, i.e. 1 safety light curtain, 1 e-stop, 1 magnetic sensor and 1 two-hand switch Possibility of remote connection through field-bus interfaces