10-05-2021, 01:29 PM
FYI, when we tested the KeyStep Pro we found that it requires its external power supply even when connected to MRCC's USB host. It briefly draws over 1A on power up, which is an extreme violation of the USB spec. Its not supposed to draw more than 100mA, and it should have inrush current limiting to prevent such high inrush current. This high inrush current trips MRCC's USB host power controller current protection, protecting the MRCC USB controller. This behavior can damage USB controllers that don't have over-current protection, so don't use the KeyStep Pro without its power supply, even if it appears to work.
The only other device we've seen with this problem is the Novation Base Station II. Use it with its external power supply or risk damaging your USB ports.
The only other device we've seen with this problem is the Novation Base Station II. Use it with its external power supply or risk damaging your USB ports.