2-encoder concept – 2 external encoders (with MOVISAFE^® CSA31A only)

There are 2 absolute encoders mounted to the drive train, which are connected to the encoder 2 and encoder 3 interfaces of the inverter. Encoder 2 is evaluated in parallel by the inverter and the safety option. Encoder 3 is evaluated exclusively by the safety option. When the system is switched on, the two absolute encoders provide a position value, so no referencing is required after switching on. During startup, the reference to the position of the application must be established once for each absolute encoder.

Both the "position" process value and the "speed" process value are calculated from the two encoders. As an alternative, an FS motor encoder or a standard motor encoder can be connected to encoder 1 and evaluated for the "speed" process value (see chapter 1-encoder concept – FS motor encoder and 2-encoder concept (with MOVISAFE^® CSA31A only).

The user is responsible for the suitability and use of the encoder system within the framework of functional safety. The user must ensure that the requirements of the required safety level (PLr or SIL) are fulfilled in accordance with the relevant standards such as EN ISO 13849 and EN 62061.