A metering system for the dosed delivery of chemical substances stored in containers (24, 25) to a dishwashing machine or a washing machine, comprising: • at least one dispenser (2, 3) having a substance inlet (2a, 3a), which may be connected to an outlet (24a, 25a) of a container (24, 25) containing a chemical substance such as, e.g. a cleaning agent, products for disinfection, water treatment or a rinse aid, wherein the dispenser has a substance outlet (2b, 3b), which may be connected to the dishwashing machine or the washing machine, from which the substance is being delivered; • a logic for controlling the operation of the at least one dispenser and of the dishwashing machine or washing machine, which logic has control means for controlling pumps, motors, valves and/or a heating system of the dishwashing machine or washing machine; • a user interface having a display and keys for operating the logic; wherein the metering system has a modular set-up, wherein the logic is divided into a dispenser logic unit (22, 23), which is contained in each dispenser (2, 3), and in machine logic unit locally separated from the dispenser logic unit and preferably installable in the dishwashing machine or washing machine, wherein the machine logic unit communicates with sensors in the dishwashing machine or washing machine and monitors and controls pumps, motors, control inputs (E1-E3) and optionally the heating system of the dishwashing machine or washing machine, wherein the machine logic unit has a power adapter for converting the mains electric voltage to a lower voltage, in particular 12 volt or 24 volt direct voltage, wherein the dispenser logic unit (22, 23) contains a rule algorithm (22a, 23a), which rules the metering of the chemical substance (24b, 25b) to be delivered by the dispenser, wherein the at least one dispenser logic unit (22, 23) and the machine logic unit are connected to one another by means of a power supply and communication bus, which has power supply lines having the lower voltage generated by the power adapter and data lines for the communication between the at least one dispenser logic unit and the machine logic unit, characterized in that the user interface is configured as a unit locally separated from the dispenser (2, 3) and the machine logic unit, which is connected to the power supply and communication bus. • at least one dispenser (2, 3) having a substance inlet (2a, 3a), which may be connected to an outlet (24a, 25a) of a container (24, 25) containing a chemical substance such as, e.g. a cleaning agent, products for disinfection, water treatment or a rinse aid, wherein the dispenser has a substance outlet (2b, 3b), which may be connected to the dishwashing machine or the washing machine, from which the substance is being delivered; • a logic for controlling the operation of the at least one dispenser and of the dishwashing machine or washing machine, which logic has control means for controlling pumps, motors, valves and/or a heating system of the dishwashing machine or washing machine; • a user interface having a display and keys for operating the logic; wherein the metering system has a modular set-up, wherein the logic is divided into a dispenser logic unit (22, 23), which is contained in each dispenser (2, 3), and in machine logic unit locally separated from the dispenser logic unit and preferably installable in the dishwashing machine or washing machine, wherein the machine logic unit communicates with sensors in the dishwashing machine or washing machine and monitors and controls pumps, motors, control inputs (E1-E3) and optionally the heating system of the dishwashing machine or washing machine, wherein the machine logic unit has a power adapter for converting the mains electric voltage to a lower voltage, in particular 12 volt or 24 volt direct voltage, wherein the dispenser logic unit (22, 23) contains a rule algorithm (22a, 23a), which rules the metering of the chemical substance (24b, 25b) to be delivered by the dispenser, wherein the at least one dispenser logic unit (22, 23) and the machine logic unit are connected to one another by means of a power supply and communication bus, which has power supply lines having the lower voltage generated by the power adapter and data lines for the communication between the at least one dispenser logic unit and the machine logic unit, characterized in that the user interface is configured as a unit locally separated from the dispenser (2, 3) and the machine logic unit, which is connected to the power supply and communication bus.