The micro USB has disconnected from the computer.
Reconnect the micro USB to the handheld computer and wait 10 seconds.
The micro USB has disconnected from the caliper.
Lossen the gland seal nut connected to the caliper head.
Remove coresponding caliper head cover.
Reconnect the micro USB to the caliper head.
Tighten the gland seal nut.
Replace the caliper head cover.