[. . . ] They react to the voltage applied and not to the voltage relative tothe operating voltage. The voltage in the measuring input without voltage divider must not exceed ±3. [. . . ] The power supply of the module comes from an external 9 V/DC power supply unit. You will have to set some soldering links for the selection of the measuring units. there is a data hold function to "freeze" the measuring value. Any usage other than described above is not permitted and can damage the product and lead to associated risks such as short-circuit, fire, electric shock, etc. Please read the operating instructions thoroughly and keep them for further reference. 0 mV in the factory, it can be adjusted according to the respective application, for example to compensate for inaccuracies of external voltage divider resistors. the contact "LKT" serves for short-term checks of the display segments. The test connection "LKT" must not be linked for more than 2 seconds, or the module would be damaged. This device can be configured for different voltage ranges, by soldering resistors to the positions RA and RB. For this module, a 0 resistor is installed for RA, which must be removed before RA and RB can be modified. [. . . ] Please set all the fields you do not need to "OFF", or they cannot be blanked out clearly. Pin 1 2 3 4 5 6 7 8 Description IN HI IN LO VDD VSS BL+ BL HOLD Function Measurement input + (0 - 200 mV/DC) Measurement input ­ (reference potential) Operation voltage +9 V/DC Operating voltage Display light + Display light Data hold (connection to VDD) Not assigned These operating instructions are published by Voltcraft®, Lindenweg 15, D-92242 Hirschau/ Germany, Phone +49 180 586 582 7. [. . . ]