Gestra NRR2-40

Details

System Description

Use level controller type NRR 2-40 in combination with level electrode type NRG 26-40 for level control and monitoring. The level controller has the following functions: ? Two level limit values with one switchpoint each (HIGH-LEVEL alarm, LOW-LEVEL alarm) ? Three-position or modulating control within a predefined proportional band ? Water level is maintained within the control band defined by the two preset limits The NRR 2-40 features optional outputs for standard signals 4 – 20 mA. The level data are transferred from the electrode to the level controller or an additional system component via a CAN data bus. The controller and the electrode use the CANopen protocol.

Function

At regular intervals the level electrode NRG 26-40 sends a data telegram to the level controller NRR 2-40. The data are transferred via a CAN bus to DIN ISO 11898 using the CANopen protocol. The transmitted data are then evaluated and allocated to the respective control range and switchpoints. Optionally a standard signal 4 – 20 mA is established for external level indication or, when used for modulating control, for the manipulated variable Y. A relay de-energizing delay can be set manually with the control terminal and display unit URB 1. To guarantee the correct functioning and safety of the system the data transmitting cycle of the level controller is constantly monitored. When the CAN bus line is interrupted the level switch sends a visual signal to indicate a malfunction and the relays 1 and 4 will be instantaneously de-energized (fail safe position).