Windows Serial Port Compatibility With eMonitor Software

Adding Serial Ports To Your Computer

Windows serial ports are numbered upwards starting from one, such as COM1, COM2, etc. Many of today's modern computers have only one RS232 serial port, or even none. If you do not have a serial port available, you must use a USB->Serial converter. These USB devices plug into an available USB port on your computer and provide one or more RS-232 serial ports for older devices.

An alternative to the USB->Serial converters are expansion cards, such as PCI cards, which must be installed on the logic board of your computer. These usually provide four serial ports, or may be combined with a parallel port. Since they must be installed on the logic board, your computer case must be opened up and the installation may be beyond the capability of the user. USB->Serial converters are much more user friendly. In most cases, procedures in this document describing USB->Serial converters will also apply to expansion cards.

USB->Serial converters may require driver software to be installed. Check for an installation CD packaged along with your USB->Serial converter. Follow the instructions which came with your particular USB->Serial converter for installation of the driver software.

Using USB->Serial Converters with eMonitor

The eMonitor software for Windows operating systems requres that the serial port used be between COM1 and COM16. However, when using USB->Serial converters, Windows may map your serial port to a port number greater than 16, such as COM17 or COM29, depending on which USB port you plug your converter into, whether or not a USB hub is used, etc. If you plug in your converter and eMonitor displays a port number above COM16, you will need to follow one of the two steps outlined below to rectify the problem so that the eMonitor software will be able to communicate with your monitoring device. Which ever method you use, you should only need to perform the procedure once.

Method 1 - Trying a different USB port

Using this method, you will unplug the USB end of your USB->Serial converter from your computer and plug it into a different USB port on your computer. Then you will reload the web page you use for accessing the eMonitor to check to see if the new port number assigned to the added serial port is within the range of COM1 to COM16. If not, try a new USB port.

  1. Unplug the USB end of your USB->Serial converter from your computer (or USB hub)
  2. Plug the USB Converter into a different USB port on your computer. Plugging into a USB hub tends to increase the port numbers, so plugging directly into the computer most often provides the best results.
  3. In your web browser, reload the web page that you use for posting your daily measurement for the device you are using (scale, blood pressure, glucose, etc.). You may do this by either quitting your browser and relaunching, or if the page is already loaded, just select Refresh from the menu.
  4. Click on the Serial Port menu to see if the port added by the USB->Serial converter is between COM1 and COM16. If it is NOT, return to step one and select a different USB port. If it is, select the port in the serial port menu and you are all done.

Method 2 - Remapping a Serial Port

A serial port may be remapped to a different number, such as changing a serial port from COM19 to COM5. This may need to be done if method 1 above does not result in a serial port between COM1 and COM16, or if you prefer to use a USB hub or a specific USB port on your computer. The following instructions are for Windows XP, but other Windows versions should be similar.

  1. Open the System Properties window by right-clicking on "My Computer" or simultaneously press the Windows and pause keys.
  2. Select the Hardware tab and click the Device Manager button to open the Device Manager.
  3. Click on the box with the plus next to Ports (COM & LPT) to disclose the installed ports.
  4. Select the port which is provided by the USB->Serial converter. The name will vary according to the make and model of the converter, as well as the software driver, but will be along the lines of "Prolific USB-to-Serial Comm Port (COM25).
  5. Right-click on the port you selected in step four above and select Properties from the contextual menu to display the properties for that port.
  6. Click on the Port Settings tab of the properties window.
  7. Click on the Advanced button to show the advanced property settings for the port.
  8. Select a COM Port Number in the range of 1 through 16. If possible, select a port which is NOT marked as "in use" in the COM Port Number menu. If all of the ports are marked as being in use, select port number 16 unless you know for sure that something is actually using COM16. You will get an alert when you close the window telling you that the COM port number may be in use by another device and asking if you want to continue.Click "Yes" to continue.
  9. Close all windows that you have opened up to this point.
  10. In your web browser, reload the web page that you use for posting your daily measurement for the device you are using (scale, blood pressure, glucose, etc.). You may do this by either quitting your browser and relaunching, or if the page is already loaded, just select Refresh from the menu. In the Serial Port menu of the eMonitor software, select the COM port which you just setup.