As a general rule, a NORD frequency inverter can process a 0/4–20 mA or bipolar analogue signal This can be set in the parameters P400–P403 (input) and P418–P419 (output), and is described in the operating instructions of the frequency inverter You have to set an adjustment of the analogue input/analogue output For some frequency inverter models, you have to adjust a DIP switch for the V/I conversion (internal resistance of the analogue input/analogue output) For some frequency inverter models, an external converter (V/I converter 10 V 20 mA, 278910315) must be connected to the analogue output For the connection of a bipolar analogue signal to the unipolar analogue input of a frequency inverter, an external setpoint converter +/10 V (278910320) can be connected