Battery Monitoring of S5-90U
What has to be observed for S5-90U regarding back-up battery?
The S5-90U is not fitted with a battery failure monitoring. If the S5-90U is shortly without power and there is no back-up battery, the controller cannot recognize, whether there is a back-up battery during the restart. This may result in a distortion of program data! Thus, try and avoid a power failure without back-up battery by exchanging the battery after one year as a precautionary measure.
More information on that can also be found in our manual "S 5-90U/S5-95U Programmable Controller System Manual", Chapter 4.4.2 (Function of the Back-up Battery), also available on the internet under Entry-ID: 1091648