The refresh pulses of ADuM3211

Hi, the ADuM3211 is employed in the isolation COMM of CAN and RS485.  Now it seems the isolator caused negative EMI issue with the GPS module nearby, when MCU is active but the COM line is unplugged. In datasheet(page 17) it mentions a periodic set of refresh pulses to ensure dc correctness, so I have questions about this mechanism.

1.What's the frequency and the duty cycle of the refresh pulses?

2.What's the meaning of the so-called "Unpower" in Table 35? Is it a real low-power state, or an assumption of the non-functoinality?

3.Can I disable the refresh pulses by disabling the COM port of MCU and unplugging the COM line at the same time?

Many thanks!