A limit breach is indicated by the built-in LED K1 and K2 (red) for each channel. The integrated relay output alarm switches the system into a safe operating state (alarm zone). The high requirements of DIN EN 61508 and DIN EN 13849 are met by a device concept whose 1oo2D structure ensures the safe detection of faults, making it suitable for applications subject to the new Machinery Directive 2006/42/EC. Safety temperature monitor STW: Protective temperature monitor with automatic reset for heat-generating systems, where an automatic reset occurs when the sensor temperature has dropped/risen by the amount of the switching differential below/above the set limit value (operating principle 2B, 2K, 2P).