IWR1843: Synchronization among a few devices

Hi,

My customer wants to use multiple IWR1843 devices(not cascading) in one system.
To avoid interferences among these boards, they wants to change radar acquisition period of each device.
i.e. one device’s “acquisition period” is “inter frame period” for others.

Questions:
Q1) I guess sync_in/out signals are used for such purpose, correct?
Q2) If answer to Q1 is yes, do we have any document which explains how to use sync_in/out signals?
Q3) If answer to Q1 is no, is there any mechanism to synchronize data acquisition period among devices?

Thanks and regards,
Koichiro Tashiro