Skip to content

UB4 Tech Notes

Communication errors when using UZ1/UB4 interfaces with RX family devices


Product: UZ1, UB4
Version: All
Date Added: 2005-03-10


Using the UZ1 or UB4 interface with an RX device can cause errors. The zBUSmon transfer test may fail resulting in a "System Test Error" error message. ActiveX commands may fail and RPvdsEx will not work properly (you may get a "Device not responding on USB bus" error message, and some components may not work, e.g. graph).


Upgrade to UB2 USB2.0/zBus Interface or Gbit interface.

Errors occur when Windows detects the UB4


Product: UB4
Version: All
Date Added: 2003-05-02


Port compatibility. The UB4 module is a USB 1.1 hub. Some newer computers now have USB 2.0 ports, which are incompatible with the UB4. Errors will occur when Windows detects the UB4 if it is plugged into a port on the computer with a USB 2.0 controller.


First, try connecting the UB4 to each of the different USB ports on the computer. In many cases, one or more of the ports will still be compatible with version 1.1 hubs. If the UB4 will not work with any of the computer's USB ports, then a USB1.1 hub PCI card can be installed in the computer and the UB4 can be connected to it instead.