An EtherCAT device is disclosed. The EtherCAT device comprises a data input port to receive a signal representing data, the signal representing one of a plurality of possible logical values; and a degradation calculation circuit. The degradation calculation circuit is to read, demodulate, and convert the received signal into a digital domain representation; process the digital domain representation into slices, where the value of the received signal at a respective time is represented in a respective one of the slices; determine differences between the respective slices and reference slices; identify an intended logical value of the received signal responsive to the determined differences; determine a quantification of error at the respective time responsive to the identified logical value and the determined differences; and determine a signal quality index responsive to the determined quantification of error.