FAQ

The FAQ list is separated into the different categories below. Note that questions that apply to more than one product will be available in each product category.

What should we think about when connecting a GPS?

Generally speaking, there is nothing different in connecting a GPS to Seaware applications compared to connecting to other GPS applications available on the market today (digital charts applications, chart plotters etc). Unfortunately the technology involved in GPS communication is old-fashioned and in some perspectives cumbersome. This is primarily due to two reasons:

• The digital output from a GPS still relies on “serial communication between one sender and one listener” (usually referred to as RS-232 serial communication), i.e. there is no built-in support for “networking” a GPS

• The information sent by a GPS still relies on the “NMEA protocol” which has not been updated since decades, i.e. GPS manufacturers have become forced to deliver products using standards of their own, thus one may well encounter problems when connecting a GPS to any PC application, why this topic is all about understanding and assisting in overcoming such problems. These guidelines are presented as “frequently-asked-questions” below.Further, it is important to know that Seaware Routing and Seaware EnRoute do not require a GPS connection. Indeed it adds features, but is still optional.

How to find cabling and/or connectors in order to connect a GPS to a PC?

The general answer is that every GPS manufacturer normally offers prefabricated cables of their own to use. Onboard large vessels, however, such prefabricated cables may not be appropriate to use due to obstacles in the way of laying the cable, or the simple fact the prefabricated cable is too short. In such case it may be required to manufacture a custom cable (see next question).

How do we manufacture a GPS-PC cable ourselves?

The following picture shows an overview of the task. The material required is:
• 9-pin female D-sub connector (international standard).
• Shielded signal cable of at least 2 wires.
• A connector to the GPS which has been designated by the specific GPS manufacturer or dealer.


The cable wiring scheme is:



*As both the logical and physical interface to the GPS is dependant of the specific GPS used, neither the signal name nor the pin assignment may be defined within this scope.

What to do when there are no free RS-232 ports (COM ports) available on the PC?

This must be solved by inserting a PCI expansion board into the PC. There are USB-serial port adapters on the market claiming to do the job, but due to several trouble reports from users, Seaware does not recommend those. They cannot harm the PC or the software, but one should be observant of computer misbehavior upon trying this solution (such as extremely slow execution of programs using the USB adapter).

What to do when the GPS only outputs data using RS-422 (instead of the PC standard, RS-232)?

This must be solved by using a signal converter or a PCI expansion board that handles the conversion from RS-422 to RS-232. All - to Seaware known - GPS receivers on the market do have at least one RS-232 output, but naturally it may be occupied by some other listening device. In such case it is possible to purchase a “RS-232 splitter” in order to split the signal from the GPS to several listening devices. It is important to understand that such splitters include an amplifier to maintain the signal strength to all listening devices, i.e. it is not recommended to simply split the wires without an amplifier.

There is a GPS connected to the PC but another application is using the GPS data. Is this possible to resolve?

This is a limitation in MS Windows in that only one application at a time is allowed to access a serial port. There are vendors of supplementary software to get around this, such as Serial Port Splitter.

What to do when the connected GPS is sending at a different baud rate from 4800 bps?

As mentioned in the introduction, the NMEA standard is old-fashioned and still designates a transmission rate (baud rate) of 4800 [bits per second]. Most modern GPS receivers offer a lot more information (per second) to be sent than possible at that rate, why some manufacturers have decided to deviate from the NMEA standard. If the connected GPS requires a baud rate different from 4800, this is currently not possible to change within the Seaware application as a user, but contact our support to resolve the problem.

The connected GPS is not sending the required message "RMC". Can we still use this GPS?

Seaware has never come across a GPS that cannot send RMC, but it may be required to configure the GPS to send it. Consult the user manual or manufacturer of the specific GPS model to learn how to configure the GPS to send the RMC message.

Is it possible to connect a USB GPS receiver?

This is possible but one should be aware the same problem as described in “What to do when there are no free RS-232 ports (COM ports) available on the PC” may occur. Also, several USB GPS receivers are known to deviate from the NMEA standard why the baud rate and other serial line parameters should be investigated before use. See “What to do when the connected GPS is sending at a different baud rate from 4800 bps”. Finally, bear in mind a USB GPS receiver without an outdoor antenna may not pickup enough GPS signal strength due to the surrounding steel structure blocking it.

What to do when the GPS is detected as a serial mouse and the cursor starts moving randomly?

It has been confirmed by Microsoft that several versions of Windows may interpret a connected GPS as a serial mouse device. Partly this causes Windows to automatically install a driver for it, which disables the COM port from use in other applications. Partly it means that the signals sent by the GPS will be taken for instructions from a mouse, resulting in the mouse cursor moving randomly on the desktop.
If possible, the best solution to the problem is to use the COMDisable tool developed by Microsoft, see http://support.microsoft.com/kb/819036.
With the COMDisable tool, the available COM ports on the computer can be disabled (or enabled) in situations when Windows incorrectly detects a serial device that is connected to the computer.
Beginning with version 5.1 of the Seaware installations, the COMDisable tool is installed in the Windows\System 32 directory.

What is Remote Desktop?

Many vessels suffer from being required to utilize and install more and more PCs, thus requiring physical space not always available.
As this problem is mainly about finding space for video displays, keyboards and mice (i.e. not the PC itself), one solution is to use a KVM-switch (keyboard-video-mouse-switch). While this may be a perfectly good solution, this topic is about utilizing the Windows technology “Remote Desktop”, technically “Remote Desktop Protocol” and further referred to as “RDP”.

To put it simple, RDP allows you to operate a different PC from the one you are sitting in front of.This is a powerful technology, but naturally it can only be used as long as certain requirements are fulfilled, described in the next section.

What are the requirements on using RDP?

Below the following terminology is used:
Target-PC the PC to get control of
Local-PC the PC sitting in front of

The requirements on utilizing RDP are:

1. The target-PC and the local-PC must be connected to a common network. It may be a local area network (LAN) as well as Internet
2. The target-PC and the local-PC must run at least Windows XP Professional
3. The target-PC and the local-PC must allow network traffic on the TCP port 3389 (most firewalls allow this by default, but may be required to configure)
4. The target-PC must be configured to allow RDP access
5. The user accessing the target-PC must have credentials (username and password) to log on to the target-PC

Requirements 1-3 are difficult to control as an ordinary user and must be supported by the company IT-policy. Requirements 4-5, however, may be configured as long as it is performed by a user logged on with Administrator privileges on the target-PC.

How to configure the target-PC to allow RDP access?

The following procedure requires the user to be logged on with Administrator privileges.

1. Open Windows Explorer (Windows Logo Key + E)
2. Right-click My Computer and select Properties
3. Select tab Remote
4. Check Allow users to connect remotely to this computer
5. Make a note of the Full computer name, for further use

How to connect to the target-PC from a local-PC?

Once the target-PC is available for RDP access, it may be taken control of by the following procedure:

1. Open Start > Programs > Accessories > (Communications >) Remote Desktop Connection (or use Windows Logo Key + R and enter “mstsc.exe”).
2. The following dialog window should then appear:



3. Enter the Computer name of the target-PC as noted in 5 above, then click Connect. (Instead of computer name, the IP address of the target-PC may be entered.)
4. Next a standard logon window should be displayed. Enter the credentials (username and password) of a granted user of the target-PC.5. Now the video of the target-PC should be displayed with the following task bar overlaying it:



6. Also, the keyboard and mouse should now be in control of the target-PC.

If the connection will be frequently used it may be convenient to create a shortcut to it instead of going through step 1) at every occasion. To do this, open Start > Programs > Accessories > (Communications >) and right-click Remote Desktop Connection and then drag it to the desired location. Then select Copy Here (XP) or Create Shortcut Here (Vista).

RDP enables to connect to any computer across the network from any other computer connected to the network. When connected, RDP gives mouse and keyboard control over the Seaware PC as well as showing its display.

How to disconnect from the target-PC?

It is recommended to always let the installed Seaware application be running on the target-PC. When connecting using RDP, consider it a loan of the target-PC. I.e. leave the target-PC in the same state as when taken control of.
This is specifically important to EnRoute Live as real time measurements are only being acquired as long as the application is running and those may become important in case of an incident.

Practically this means:

1. Do not shut down the running Seaware application
2. Disconnect by clicking the X in the RDP task bar.

How to shutdown or restart the target-PC?

There may be occasions when it is needed to shutdown and restart the target-PC, for instance upon a software upgrade. But when being remotely connected to a target-PC, the standard means for shutdown and restart normally available will not be offered. The reason for this is security. I.e. one should not involuntarily happen to restart the target-PC which usually is only at loan.

Still it may well be required to perform a restart of the target-PC, especially if the target-PC does not have any display, keyboard and mouse of its own.
The way to do this is to press Ctrl+Alt+End. Notice the similarity to pressing Ctrl+Alt+Del, but this will always pass control to the Windows Security page of the local-PC.
With Ctrl+Alt+End, control is passes to the Windows Security page of the target-PC instead, where such tasks as Restart, Task Manager etc may be performed.

What are the drawbacks of using RDP?

While RDP is very powerful, there are drawbacks compared to actually sitting in front of the target-PC. Mainly this is about using the physical resources of the target-pc, such as:

• CD/DVD drives
• Floppy drives
• USB ports
• COM ports
• Installed printers

Consult Microsoft Windows documentation for a better understanding of these limitations.