Latitude 5480 with D3100 docking station

The D3100 uses a DisplayLink chip to provide video output rather than tapping into the GPU's native outputs, which means you need to install the DisplayLink software, which you can find at DisplayLink.com.  That's Step 1 of the "Connecting the dock" section of the D3100's manual -- did you take a look at that?  That said, DisplayLink technology has a lot of downsides compared to using native GPU outputs especially if you'll be using your external display for anything beyond regular productivity content, and since you have a 5480 that includes a USB-C port AND just bought that dock, you should really consider returning it in favor of the WD15 dock.  Not only does it use the GPU's native outputs, which means it's free of the downsides of DisplayLink, and it would actually be able to charge your system through the USB-C cable, giving you a nice single cable solution.  The D3100 is intended to offer a dock option for laptops that don't have a USB-C port or a "legacy" docking connector and where USB-A "regular USB" is their only option.  It's definitely better than nothing, but you can do much better given that you have a 5480.  And the D3100 isn't even the newest DisplayLink-based dock; that would be the D6000.

Also, how are you connecting the D3100 to the USB-C port?  The D3100 uses a regular USB-A connector, so either you're using a USB-C to USB-A adapter in order to connect the dock to your system, which seems unnecessary given that the 5480 has USB-A ports, or you're actually using a D6000 that DOES support connecting to systems via USB-C in addition to USB-A.  In the latter case, the need to install the DisplayLink driver remains the same, and the D6000 does add the benefit of being able to charge the 5480 when connected via USB-C, but the WD15 would still be a better choice.  The D6000 is aimed primarily at businesses that have a mixture of USB-C systems and older Latitudes that use a traditional docking connector, because the D6000 allows them to standardize on a single docking station model to support both types of systems.  This is especially convenient for companies that use "hotel desk" arrangements where people don't have assigned seats and therefore can't always have a docking station for their specific system model waiting for them.

I confirm that the station I have is a D3100.  I purchased a cable that has the USB-C connector on one end.  I thought that I might have better performance using the type C (probably wrong on that thought).

Thank you for the responses.  I am currnetly working here in Malaysia so I will not be able to return the unit but instead will have to make due for now. So, sounds like I need to install the Display Link driver first.  Being that this is a Company laptop, I will need to have IT authorize that.  Will comment back here once I get beyond this step.

On the issue of compatibility, I notice on the Dell-US website (http://www.dell.com/en-us/shop/dell-docking-station-usb-30-d3100/apd/452-bbpg/pc-accessories), under the details of the D3100, the compatible laptop list does not include the Latitude 5480. 

However, on the Dell-UK website (http://www.dell.com/en-uk/shop/accessories/apd/452-bboo), it does list the Latitude 5480 as compatible.

Why would these lists be different? And, is my laptop indeed compatible with the D3100?

Thanks

That's just a listing discrepancy.  It's not at all uncommon for Dell accessory pages to leave off systems that are compatible (sometimes there are just too many to list), and sometimes they'll accidentally list systems that AREN'T compatible.  The D3100 is compatible with any system that has a USB port and is running an OS that can accept the DisplayLink drivers, including non-Dell systems.

Thanks again for the clarification.  I was finally able to get the DisplayLink driver installed and it solved my issue.  Everything on D3100 working well now.  Cheers and good day.