Background

One of the components of just about every navigation PC setup is the USB Serial Adapter. These adapters are used to interface a PC to GPS receivers, NMEA 0183 adapters and multiplexers, AIS receivers and transponders, and many other types of marine electronics. Most USB GPS receivers even have a USB Serial Adapter embedded within them.

Several companies make the integrated circuits ("chips") that form the core of a USB Serial Adapter. Each company provides special software, called a driver that allows Windows to detect and operate the USB Serial Adapter. If the appropriate driver has not been correctly installed in Windows, the USB Serial Adapter will not function and will not appear in Coastal Explorer’s list of Data Ports.

Because driver software needs direct access to the hardware it controls (in this case, the USB Serial Adapter), it is given special privileges by the operating system (Windows). Unfortunately these privileges make it possible for a poorly written driver to bring down the whole operating system when it crashes. (Normal applications are not given the same privileges and when an application crashes, the operating system and other running applications are not affected.)

When a driver crashes, one of three things will usually happen: 1) the computer reboots all of a sudden, 2) the computer completely locks up, or 3) you see a "Blue Screen" (BSOD) with a lot of technical looking words and numbers on it.

If you experience sudden reboots, complete lockups, or Blue Screen errors, a device driver is certainly responsible. Unfortunately it is not always easy to tell which driver is at fault because every bit of hardware in your computer, including the display adapter, hard drives, keyboard, and mouse uses a driver. Sometimes, after rebooting after a driver crash, Windows will offer to send a report about the crash to Microsoft, and sometimes you will get a message back indicating which driver caused that problem, but this doesn’t always happen. However, if you seem to only experience these problems when running Coastal Explorer or Rose Point ECS, chances are that the problem is being caused by a USB Serial Adapter driver.

Your first step in trying to solve driver problems should be to check the website of the manufacturer of the device with the driver that is causing the problem. Most manufacturers have an area where you can download the latest drivers in the support areas of their website. If you need help determining which driver you need or installing the driver, please contact the manufacturer of the device; Rose Point cannot offer support for other manufacturer’s devices.

A Special Note About Prolific Adapters

One very common USB Serial Adapter chip is made by a company called Prolific. Unfortunately many users report that the drivers for these chips are notoriously buggy and are a huge source of blue screen errors and other problems. You can usually tell if you have one of these chips because the port’s name will contain the word "Prolific", but this is not always the case.

Some people have had some success finding just the right version of the Prolific driver for their version of Windows. (Unlike most drivers, the latest Prolific driver is not always the best.) However, we feel that your navigation system should just work, and not be dependent on something that might cause your PC to spontaneously reboot. As such Rose Point does not recommend the use of any devices that use the Prolific USB Serial Adapter chips, nor can we offer any support related to their use.

Below is a list of devices known to contain the Prolific USB Serial Adapter chip (this is not a complete list):

• US GlobalSat BU-353W
• Zenstar III
• Nasa Marine PC Navtex USB (however the USB Serial Adapter can easily be replaced)
• Brookhouse NMEA 0183 Combiner/Multiplexer
• Gigaware USB to Serial Cable (Radioshack - this is one of several they have sold over the years)
• ATEN UC232A USB to Serial adapter

What Works Well

Rose Point has found that the USA-19HS and USA-49WG USB Serial Adapters made by Tripplite/Keyspan generally work very well (though the USA-49WG lacks support for 64-bit versions of Windows). In addition, USB Serial Adapters that use chips from FTDI also work with the latest drivers. Here are several devices that seem to work well:

USB GPS

• Rose Point Portable GPS
• Rose Point Fixed Mount GPS

USB/RS-232 Adapters

• Keyspan USA-19HS 1-port USB Serial Adapter
• Keyspan USA-49WG 4-port USB Serial Adapter (not for 64-bit Windows)
• Sabrent CB-FTDI 1-port USB Serial Adapter (FTDI based)
• SerialGear USBG-BAY4 4-Port USB Serial Adapter (FTDI based)

Note: SerialGear has an enormous selection of USB to Serial adapters. If you decide to purchase an adapter from them, be sure that it is not a Prolific based adapter. In the description of their adapters it will usually say, but sometimes you need to read through the detailed description very carefully in order to be sure.

Other Converters and Multiplexers

• Actisense USG-1 USB to NMEA 0183 Gateway
• Actisense NGT-1 USB to NMEA 2000 Gateway
• Actisense NDC-4 NMEA Data Multiplexer 4
• NoLand Engineering NM42U USB NMEA 0183 Multiplexer
• ShipModul MiniPlex-USB NMEA 0183 Multiplexer