High-quality USB hubs extenders do not reduce the data transfer rate from Time Taggers to the PC.
We tested three different USB extenders using a Time Tagger X connected to a USB 3.0 port of our PC (CPU AMD Ryzen 9 5950X 16-Core 3.40GHz) with only essential processes in the background. The results are independent of the model of the extension. The measured rates are:
For longer distances, optical extenders can be used.
In case one would need to buy a USB extender, here are some recommendations that we tested:
In particular, the 350 m-optical extender was tested with 300m-long OM3 and OM4 fiber cables. The tests were performed on multiple PCs with good results in almost all cases. No particular improvements were measured when using OM4 instead of OM3 fibers.
The Time Tagger 20 is powered over USB. Therefore, the extender should also be powered to provide a stable power supply. RJ45-based connectors have been working well with the Time Tagger. We have tested one from VTOP (up to 50m).