Encoder evaluation with MOVILINK^® DDI

When starting up 2 safety encoders with MOVILINK^® DDI on the MDD91A double-axis module with one CSS21A safety option each, the axes must be started up one after the other.

The second encoder may only be connected if the first safety option, the safe MOVILINK^® DDI connection to the encoder that was first started up, is fault-free.

If both encoders have been started up or replaced at the same time on an MDD91A, you must check whether the CSS21A safety option and the safety encoders with MOVILINK^® DDI are correctly coupled with each other.

This can be achieved by physically disconnecting an encoder/motor system from the basic unit in the switched-off state and checking whether the expected safety option indicates a fault or a warning and whether the other safety option runs fault-free. This requires the entire system to be switched on and off several times.

As an alternative, move a drive in manual mode and check in the diagnostics of the safety option whether the encoder values change. If the encoder values change, the encoder is correctly coupled. Repeat the test with the second drive regardless of the result of the first drive.