I have a customer who is using the AD2S1210 Resolver-to-Digital Converter in extended phase lock mode. This is accomplished by setting bit D5=0 in the Control Register (see Table 22 on page 23 of datasheet). He is measuring 100 degrees of phase difference between the excitation frequency and the input. However in the Fault Register bit D1=1 (fault condition: out of phase lock range). So my questions are: 1. Is this normal every time phase is greater than 44 degrees (normal phase lock mode)? 2. Has anyone else encountered this and have an idea what may be the cause?