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FAQ: General

FAQ: General >>>

This might be due to the VHF antenna you are using. However, there is a solution for it. Please, connect the antenna cable of the car radio „without ground“ to the easySPLIT, i.e. only the inner conductor/pin is to be used. Do not connect the outer conductor/cable which is connected to the ground of the chinch plug or to the ground of the car radio!The physical effect put in a nutshell: An antenna is always a dipole. Normally the inner conductor of a coaxial cable is connected to the upper dipole and the outer conductor is connected the lower dipole of the antenna. However, the customary antennas for pleasure crafts do not have a lower dipole. This lower dipole is simulated by an adapted network (i.e. simply a high-frequency transformer). The adapted network is adjusted to a frequency range of approx. 150 Mhz to 163 Mhz. Thus, the outer conductor of the antenna cable has the important function to adjust the antenna to the frequency range of 150-162 Mhz.

So, if you do not use the outer conductor, colloquially called “ground”, for the car radio plug, you simply have a „cable antenna“ for the car radio which should work fine for the VHF radio frequency range.

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Please, turn it on.Furthermore, a too high voltage drop due to a small cable diameter might be the reason. This voltage drop (Ua) can be calculated as follows:Ua = (lxpxI)/A

l = length of the wire (e.g. 10 m)

p = specific resistance (spoken: rho; copper = 0.0178 ohm x mm²/m)

I = current (e.g. 1A (ampere))

A= cross-section of the cable (e.g. 0.14 mm²)

Example calculation:

If you used a fairly thin cable (0.14 mm² cross-section) for the extension, the total cable length amounts to 10 m, the voltage drop would be about 1.3V. Due to this drop it may be possible that the internal voltage regulator will no longer be supplied with sufficient voltage and thus does not work properly. Another cause might be a simple short circuit (direct connection from + to -).

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The basic question is, whether the Powerbook has a serial COM interface (RS 232).
Some laptops do not have it. You can help yourself with a USB-to-COM adapter (which can be bought at e.g. Conrad, Media Markt, Saturn etc.).

The Apple or PC software (e.g. a terminal program) uses this COM interface and shows the encoded telegrams (ship reporting etc.), which have been received by the easyAIS. As the easyAIS works according to the NMEA0183 standard, the information is received as ASCII-telegram at 38400 baud (start and stop bit, no parity). Every common terminal program – no matter on which PC or Apple – can display these characters. In order to decode the AIS information you need a special software (e.g. a card plotter program with AIS functionality).

You can find a PC software on www.yacht-ais.de. Unfortunately, we cannot say whether it works with Apple or not.

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FAQ: General >>>

On November 6, 2006 we changed some program parts in the firmware, since that time all NMEA data is passed through.

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We recommend a minimum distance of 80 cm. (e.g. Simrad recommends 100 cm).Please note: Regardless of the distance of the VHF antennas to one another, the antennas should be mounted as high as possible. The higher you mount the VHF antenna, the better is the transmission.

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FAQ: General >>>

The frequency range of the VHF radio output is limited to 108 MHz, i.e. higher frequencies cannot pass this output. For this reason, the reception of DVB-T is not yet possible.

Information: The reception of wave bands outside the VHF range is not possible with most frequently installed VHF antennas, i.e. in the best case the lower range of the VHF-DVB-T-band may be received. The reception of higher VHF wave bands requires a change to a multi-band antenna. Due to the commonly used coaxial cables (RG58/RG213) and coaxial plug-in systems (PL259/SO239) the transmission and reflection losses in the plug and socket connectors increase at higher frequencies to such extent, that adequate reception of higher frequencies would only be possible with a loss of quality. For this purpose it would be necessary to replace the used plugs and sockets by VHF-suitable versions.

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If you want to operate a DSC radio unit or the AIS transponder easyTRX on a ship, you need a license for this radio unit.You can obtain it from the Bundesnetzagentur (Federal Network Agency). The Federal Network Agency of your radio station will send you a MMSI number, which should then be programmed into the easyTRX. If you already have a MMSI and would like to operate an additional easyTRX, you need to send a notification of change to the Federal Network Agency.

Then, please program your existing MMSI into the easyTRX. The following link provides detailed information:

Bundesnetzagentur Aussenstelle Hamburg Sachsenstr. 12 und 14 20097 Hamburg Tel.: 0049 40 23655-0 Fax: 0049 40 23655-182 email: seefunk@bnetza.de   http://www.bundesnetzagentur.de

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FAQ: General >>>

When the red light flashes, the easyAIS is receiving messages. If there is no object in the proximity, the light is not flashing and nothing will be displayed on the plotter screen.

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Unfortunately, as far as we know, no such unit is available on the market. Currently, only our active splitter for AIS transceivers is available. In order to realize your request, we suggest following:

  • AIS transceiver – easyTRX
  • AIS Class B active splitter – easySPLIT OCB
  • We recommend the “Infobox WIB3″ as weather fax

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FAQ: General >>>

Although you just want to transmit, it is necessary to have both antennas. The unit must receive the exact position, in order to transmit your position. So you need a receiver to get your position and a transmitter to send your position.

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FAQ: General >>>

The plotters Lowrance HDS 5 and HDS 7 feature a differential type input for connecting external NMEA devices and therefore they require a bipolar signal at these points. Most commercially available AIS devices, transceivers and receivers are equipped with standard unipolar outputs. Our devices are built according to this standard.

The easiest way to solve this problem is to connect a capacitor  in-line with the NMEA positive signal between the NMEA output of the AIS device and the NMEA input of the chart plotter. Thus a 100% function is ensured.

Please use the inputs and outputs at 38400 baud, to avoid traffic congestion and potential loss of data at high AIS traffic volumes.

Please, note the following requirements for the capacitor:

  • Value: 100nF
  • Ceramic or plastic, does not matter
  • Voltage:> 16V DC

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By each AIS channel there are 2250 AIS position updates possible.
That means that on both frequencies (161.975 & 162.025MHz) 4500 messages can be sent.

An AIS position report (Msg. 1/18) is send by a VDM-Message. This message has a length of 50 Bytes.
One Byte contains 10 Bits (8-Vit plus one start and stop bit)

So one VDM = (50Bytes *10) = 500 Bit

If there would be a channel load of 100 percent, the calculation would be as followed:

4500 (max. VDM messages per minute / 60 = 75 (VDM/second) Therefore 75 AIS position messages could be received per second.

From the beginning we know that one VDM has 500 Bit

75 * 500Bit = 37500 Bit

So on a channel load of 100 percent there will be 37500 Bit / s.
The baud rate of 38400 is perfect then.

But what does that mean for a chart plotter which is only able
to handle a 4800 Baud rate (Bit/s)?

4800 Bit / 500 = 9,6

With this baud rate you only can receive 9,6 VDM messages and this is already a channel load of 12,8 %!

But now we come to the next problem because an AIS transceiver is not only transmitting VDM messages which it receives to the chart plotter. There are also GPS messages and some prop. strings (LED status, info about voltage, diagnose sentences, etc.)

Let´s have a look on VDM plus GPS sentences and take three of them which are standard:

  • GPRMC: (RMC = recommended minimum sentence)
  • GPVTG: Info about SOG and COG
  • GPGGA: one of the main sentences, contains time, position including height and signal strength)

All of these three sentences will be transmitted every second and they have a length of ~2000 Bit.

Lets subtract the 2000 Bit / s from 4800 Bit/s and we have only 2800 available Bit/s.

2800 Bit / 500 = 5,6; now there are only 5,6 VDM / s!

And this is only 7,5% channel load which you will have very fast in some areas.
For example the highest meassured channel load from a pleasure boat was in
Rotterdam, Singapore, Shanghai with 40-50 percent!
In a near distance to waterways you can have 20-30 % very fast!

Overview:

Baudrate GPS [ON/OFF] Max. VDM/s Max. channel load[%]
4800 GPRMC,
GPVTG,
GPGGA
5,6 7,5
4800 Off 9,6 12,8
38400 GPRMC,
GPVTG,
GPGGA
72,8 97,1
38400 Off 75 100

 

Result:
If you are crossing and sailing in areas with waterways we really recommend using always the high baud rate of 38400 to not lost AIS position updates!
If you just drive within Non-High-Traffic zones 4800 Baud is ok when you switch off GPS sentences. For example the easyTRX2S can be set to „None“.

baudrate

Example: easyTRX2-S settings within the Programming-Tool.

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Reasons can be various.

Amongst other things, the reason could be that you are out of range of the receiving station of this web-services.

Also it could take some time to see all your data there, it is not 100 percent live!

 

To check if the other vessels receive your position, just ask them by your VHF radio.

This is the easiest and most effective way.

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To get AIS/GPS data by WiFi on your PC some navigation softwares need a COM port.
Now you have to send data from TCP/IP (from WiFi-Board) to your PC.
This is done by a VSPE-Tool (Virtual Seriell Port Emulator).
We use it from www.eterlogic.com

We recomment to download the file from our page here(WiFi-COM-Tool)
as we already gave the right settings there for you:
https://www.easyais.com/downloads/software/software_allgemein

Please unpack this zip file and start the setup procedure.

After this you should see an icon on your desktop, please start this.

After a few seconds a green symbol is seen below right of your desktop.
You an click on this to set more settings.

If the window is empty you can load the right settings which are also contained on this ZIP file.
This is called config-V1.vspe or config-v2.vspe.
V1 is only used in old WiFi modules. So please try v2 first.

When you need further assistance you can send us an email to support@weatherdock.de

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