No USB on that board. It is genuine hardware RS-232 via a DB9 connector. No USB latency if your hardware supports it. It does route the the PPS to the connector at RS-232 levels so you do have a propagation delay through the level shifters. I tend to use real RS-232 interfaces instead of USB because micro-controllers have much better (and easier) support for it... plus I live in the Land of the Obsolete... Also the board can be used as a general RS-232 level shifter for other projects... I added the ATTINY pads for making a device with a 10 degree of freedom IMU board... I use the low order bits from the noisy readings of the MEMS IMU sensors to generate cryptographically secure true random numbers. The numbers that it generates pass all statistics tests for randomness. Plus the IMU can detect movement of and tampering with the device and generate an alarm.