In the access control system to set the door card permissions registration failure is the reason
You can use a separate power supply, power supply lines or less than the square of the cable, you will have the above problems
The port is generally not bad, try another USB interface, and some USB power supply, it is recommended to plug the host behind the USB interface first registration failure may be where you did not set up the best is to find you supply, different Manufacturers will be different systems
The card reader I have seen usb and 485 rpm 232 .... you say the situation I suggest you first in your software system settings in the selection of the computer port is correct. And then check whether the usb or transcoder is normal. The The The No problem left the computer port is not unstable. The The The The Hide Avg United Statess.s.Haintithers.ithertv United Statess.s.ither wanted outcome
