SICK has released the IN 4000 inductive safety system. It is friction-free, immune to vibrations, easy to install and unaffected by dirt.
The system and its individual sensor and relay evaluation units are certified for Category 4 use according to EN 954-1. The sensor of the IN 4000 can be connected directly to a safe PLC.
The basic version of the IN 4000 consists of an inductive sensor in a cubic housing, and a relay evaluation unit. The noncontact operation of the inductive safety system provides the advantages of simple installation and adjustment as well as increased immunity to impacts and vibrations.
If the machine or plant to be safeguarded is controlled by a safe PLC, the IN 4000 sensor can be run directly on it. This is possible because the sensor's input and output signals are designed to correspond to EN 61131-2 and are thus compatible with the I/O signals of a safe PLC. Control Category 4 according to EN 954-1 is maintained even if the maximum number of 10 sensors is connected in series. If there is no safe PLC available, the sensor is connected to the IN 4000 evaluation unit with relay outputs. Here, too, the connection of up to ten sensors is possible - leading to considerable cost savings, particularly in the case of complex machines or plants. Three safety-relevant N.O. contacts, two N.C. relays and integrated external relay monitoring also allow flexible integration in the particular machine control system.
As a result of the inductive operation principle no separately coded actuator is required. The sensor directly detects the presence or absence of metal. The switching area of the sensor is monitored in terms of both time and space to provide the necessary prevention of simple tampering. Unauthorised alterations are detected and lead to the machine being safely switched off.
The IN 4000 is suitable for detection of position and the safe monitoring of protective doors on machines and plants.