ProCal uses the FTDI D2xx drivers to communicate with Transmille Devices to support a more reliable connection than the default windows communication port methods.
If ProCal indicates on startup that no FTDI devices can be found, follow the steps below:
1) Ensure that the correct FTDI drivers installed. The recommended drivers can be downloaded from here: http://www.transmille.net/USB%20Driver%20%5bFTDI%5d/CDM%20v2.10.00%20WHQL%20Certified.exe
2) Open device manager on your computer and Look for the section labelled 'Ports (COM & LPT)', expand this tab and check that all of adapters/cables that you have connected are listed. Disconnecting a device and replugging in should cause the device to disappear and then re-appear to confirm each connection is present
3) Ensure that listed devices are provided by FTDI and not any other manufacturer. All Transmille products with direct USB connections use FTDI modules, but if you have used a 3rd party RS232 to USB adapter this may not be FTDI devices and will not operate correctly. This can be checked by double clicking on any listed USB Serial Port in Device Manager
4) Ensure that no devices are in the 'Unknown Device' status in Device Manager
5) If the USB devices are not detected, try another USB port or disconnecting any USB Hubs and go directly to your computer to confirm that your USB hub is working correctly.