Switching-amplifiers of the series ESA2 NR are concepted to have a compact unit to measure signals of one or two sensors and to monitor them according to the limit values. Two different programs are selectable to have one sensor or two sensors (total load, single load and differential load) with each 6 relay functions. In the same time the values of the sensors are used to control the life time of the used winch (safe work period recorder). All measurement, calibration and cut off values and the actual value of the safe working period recorder can be rread by the integrated display. With the four keys all settings can be done. Alternative all settings can be done by PC. When the limit values are exceeded five relays are switched in relation to the configuartion. One relay is used for control of the plausibility of the sensors or detection of other alarms. Additional its possible to connect an large numercial display.