The PGS 400 pump control unit assigns a level with the unit “m water column” to the standard power signal 0/4 … 20 mA supplied by the transducer (in the case of pressure the unit “bar” and in the case of flow quantity the unit “l/s”).

Scaling e.g. for the level, is either via the maximum value from the transducer (ETG) at 20 mA or via the actual value (momentary value). The scaling is defined in steps of tenths or hundredths. The indicator value is calculated according to the input power and the scaling that is set. It is also possible to provide a scaled percentage indicator. The value of the analogue output changes in accordance with this scaling whereby 100% corresponds to 20 mA or 5/10 V at the output.

All the limited values can be determined with the measuring range. For all three limited value pairs the turn-on value can be above or below the turn-off value (fill or empty tanks). Cyclical alternating of two or three limit value contacts balances the load of the connected pumps to ensure uniform wear.

A high degree of operational safety is ensured by the measuring system being continuously supervised. Errors, cable parting or short-circuits, corresponding to the lower deviation from the programmed zero point or the permissible input power being exceeded, are indicated in clear text and also as a potential-free fault. The parameter setting for all functions does not require additional programming equipment and is carried out with 3 keys. For the sake of easy operation it is fully menu guided.

A separate constant voltage supply provides the transducer with the auxiliary power required.