How to generate Frame Clock(FR) of the ADC?

Hello everyone,

I'm using a FMC board card with ADC - LTC2174. After power on，I can detect DCO signal of the ADC with Oscilloscope. However I can't detect FR signal.

1. I think that FR signal will be automatic generated after power on (just like DCO signal). Is that actually true?

2. I don't connect analog inputs of ADC. Must analog inputs be connected in order to generate FR signal?

Thanks