Wiegand Interface - Crosstalk and EMI

• Wiegand data transmission is not differential, meaning that all of the 0's are transmitted down one line (D0) and all of the 1's are transmitted down the other line (D1)
• Using a non-screened or shielded cable such as Cat5E for Wiegand data transmission makes the connection susceptible to EMI
• The oscilloscope image above shows the data sent on the left and the data received on the right. The Data Received shows the effects of EMI that makes it difficult to discern where the highs and lows are, potentially corrupting the data. This interference can cause data to be lost and card reads to fail.