About 3DM-GX5-25 time synchronization problem

[xuchengjie19981030]

Hello, I am using your product :3DM-GX5-25, I want to use gps to hard synchronize time between 3DM-GX5-25 and livox mid360, I have successfully synchronized Livox mid360 and gps. At the same time, I connected the pps1hz output of gps to the No. 7 interface of 3DM-GX5-25. I would like to ask you the following questions:

1: Now I want to use the ros driver（microstrain_inertial_driver） to get the synchronized data, do I need to modify anything in the ros driver or other places?

2: How to measure and determine the success of synchronization?

3:cinfig file has a filter_enable_external_gps_time_update value, but my computer does not seem to output gps time topic? Must this option be used?