Problems with communication with I/O units
Maintenance/Troubleshooting
1-84
1.5.7 USB transfer cable is not recognized.
Is the USB transfer cable connected?
Cause
The USB transfer cable may not have been correctly connected.
Solution
Reconnect the USB transfer cable or reboot the PC. Connect the USB transfer cable
directly to the USB port, not to a USB hub.
Is a USB hub used?
Cause
Electric power from the USB hub may not have been sufficient.
Solution
Use a powered USB hub. Or connect the USB transfer cable directly to the USB port.
Check if the powered USB hub complies with the Universal Serial Bus 1.1 or later.
Does a “?” or “!” mark appear on the Device Manager?
Cause
The USB driver may not have been installed properly.
Solution
Uninstall and then reinstall the USB driver. Refer to the following section for the instal-
lation method.
)