The Davis Weatherlink software comprises three distinct components:
- The main Weatherlink for Windows program itself;
- Separate software units known as ‘drivers’ that work within Windows to deliver data to the main Weatherlink (WL) program from whichever PC connection the logger is connected to;
- Any optional expansion modules that may be installed. The module that enables uploads to Weather Underground is the commonest, but the Davis Email/Phone and Agricultural modules are other examples;
The main Weatherlink for Windows program is written by Davis themselves. It has absolutely no known Windows compatibility issues whatsoever and is hardly ever the source of communications or other software issues. For this reason, it is rarely necessary or useful to try reinstalling Weatherlink itself. (Running the reinstall routine can however help to reinstall USB drivers, but there are other ways of doing this.) Instead, WL-related problems typically will have one of five causes:
- A simple stall in communications that can be easily fixed by rebooting logger and/or PC;
- Driver problems;
- Electrical interference;
- Corrupted hard disk files;
- Incorrect (eg wrong date-stamp) or corrupt data in the logger itself;
Each of these types of problems is discussed further in the notes here.
Drivers are not written by Davis, but by third-party companies, although the driver for the USB logger is distributed on the main WL CD. Communication issues usually only ever arise with the USB driver. (There are also both serial and network drivers active behind the scenes for the serial and IP versions of the logger, but these hardly ever cause problems and so are not discussed further here.)
Expansion modules are also rarely the cause of problems and so are also not discussed further here, other than to note the obvious point that the extra features offered by each supplementary module will not be available until the relevant module has been installed and activated. See the ‘Expansion Module’ topic in the main Weatherlink online Help for further information.
The USB driver is written by a company called Silicons Labs who manufacture the USB chip used within the logger – the driver is a small specialist piece of code that communicates directly with the USB chip. Both main WL software and the USB driver are supplied together on the WL CD and the installation routine should install both components without problem. But it is important to appreciate that any problems communicating with USB logger are almost always related to the USB driver not being installed or configured correctly and are very unlikely to be directly connected to the main WL program. In other words, communication problems will typically be a driver issue and not directly a Weatherlink program problem (which doesn’t make them any less frustrating of course, but it’s worth knowing where to focus attention in order to try and fix the problem).
If necessary, the driver can be reinstalled or tweaked independently of installing the main WL software. For example, the driver can be downloaded from the Silicon Labs website, the driver package being called ‘CP210x USB to UART Bridge VCP Drivers’ (CP210x being a reference to the specific USB chip that the USB logger contains). NB Note that the driver documentation is not always fully up to date, for example at the time of writing the driver v6.7 is described as being compatible with Windows up to v8.1, but is in fact also fully compatible with Windows v10.
Important: There are two distinct USB drivers!
New users often fail to appreciate that two distinct USB drivers are provided because the USB logger can actually operate in one of two different communication modes, which are referred to as ‘Serial’ and ‘USB’, and each mode uses its own USB driver. Yes, even though it is a USB logger, one of its modes is referred to as ‘serial’. More formally the two modes are:
- Serial = Virtual Com Port (VCP) mode, which is a mode similar to a traditional RS232 serial connection;
- USB = USBXpress (USBX) mode, which is a native USB-based mode;
To be clear, in both modes the physical connection to the PC is via the same USB connector – it is, after all, a USB logger and so can only connect to the PC via a standard USB connection. But the ‘serial’ or ‘USB’ mode refers to how the data is handled internally in the PC once it arrives at the USB port.
The logger should always be set to one mode or the other. It should remember which mode it’s in even when powered off and should always resume in that same mode. Each mode requires a different driver to be loaded, which should happen automatically at startup when the logger’s current mode is detected.
It is important to understand which logger mode to use or which mode is active. Failing to do so is a significant cause of frustration and support calls – please see the Understanding the USB logger modes topic for further detailed information.