FAQ: easyTRX

You can do both, by software and also with an external switch.
We lead two cables out, a black one and a mauve one. If these two cables are connected (e.g. by means of a switch) the easyTRX works only in the receiving mode. If the cables are not connected, it works in transmitting and receiving mode.

Yes, normally no problem. But you have to check whether the C70 is already AIS capable.

If you find an “AIS topic” in the systems configuration if it is AIS capable. If there is no “AIS settings” you probably have to make a plotter software update first. For that please contact your Raymarine dealer. Also please check, whether the NMEA port is “free”. If this port is occupied with another unit and a different data speed in comparision to the easyTRX (easyTRX has got 38400 Baud data rate), than you might need a multiplexer to get the data with different speed into one NMEA port.

You need a PC only one time at the beginning to enter your MMSI and the rest of the ship data like name, length, etc. etc. After this is programmed you do not need anymore your PC.

Normally each chart plotter which is able to display AIS has got the possibility to set an alarm. This alarm is called “CPA” = closest point of approach. Normally you can set this to 5nm and every vessel which comes closer would initiate an alarm at the plotter. Also it is the same with the most PC navigation software, which are able to display AIS. There should also be a setting.

If you do not use, either a lotter, nor a software I could recommend “Yacht AIS” from the company Y-tronic. They have a very simple, but very nice software which shows the other ships in a radar screen and which gives you also an alarm on the PC if the ship is in your CPA range.

Following is the reason: Class B transmitters, as ours, work within a process which is called SOTDMA. (self organized time division multiple access). This means the big vessels listen to the traffic and the information containing in all other telegrams and defines it’s own raster of transmission timing, which is then distributed to all other participants within the radio range. Our class B transmitter, as all the others too, is using a “listen-before-talk-method”. This means, that before transmitting, a ship has to observe the radio transmission timeslots, whether to be allowed to transmit, if the timeslot is not occupied, or whether to wait for a free time slot. A timeslot is very very short (app. 25ms). Therefore the starting time of a class B telegramm must be very exact on time. This is only possible by a microsecond exact timebase. Normal GPS antennas do have an accuracy of 1 sec., sometimes a little bit better, but not as exact as necessary. With the GPS antenna which can be purchased from us the microcontroller inside the easyTRX is calculating the timebase in microseconds and therefore it is proofed that the telegramm is transmitted exactly when it is allowed. With a normal GPS antenna this would not be possible.

The combination antenna is easy to mount and works very well.

The quality of the reception is very similar to a regular VHF antenna. The difference is the height of the antenna in which the combination antenna is mounted normally. A typical mounting place of the combination antenna is the railing at the stern of the ship. This “mounting” height is much less than the height of the masttop. In our practical use we found out, that the transmission range and the reception range is more or less the half. With our easySPLIT OCB and the masttop antenna you have a typical range of app 8nm for the transmission of your AIS data and app 25nm for the reception of other AIS data (Depends of course of the antenna and cable quality, as well as of the weather!) This is simply due to the reason of the physical effect of the VHF (Distance is line of sight and you know, as higher, as better).

“There is not such a good amplifier existing than a high mounted antenna!”

It is easy. We already have a cable with two wires inside the cable tree which is defined for this use. The colours of the cables are violet and black. If you short out these cables via a lever key the easyTRX will be getting in a pure reception operation and does not transmit your ship and drive data.

With reference to the cable we did the following: The exsiting cable is already 5m long. We tested the VHF/GPS combination antenna with an additional 10 m long cable. At the end the total cable length was 15 m. The additional cable was a simple RG58 cable. It had a male TNC plug and a female TNC plug as extension plugs between the existing cable and the TRX. The plugs were crimped to the cable. This worked very well. All the satellites in our hemisphere were visible.

Therefore we can guarantee a 100% working for a cable length of 15m with RG 58 But as you know as better the cable is, as better the reception and transmission will work.

Please note that you need a seperate GPS Antenna for the Class B transceiver.

The antenna which is on board, does not work probably. The normal GPS antenna are „active“ antenna, which are already sending a coded telegram (NMEA 0183). These telegrams are perfect adapted for PC programs and cardplotter. Most telegrams are only closely for 1 second or 1/10 second. That is to incorrect for a class B AIS transmitter. The timebasis for AIS radio communication must be closely 1ms also a/1000 second. This accuracy will be reached when the GPS antenna is sending the raw data to the Class B AIS tranceiver also easyTRX. The raw data are transmitted from easyTRX into the correctly time base.

Thats why you need an seperate GPS mushroom-typ antenna, which send the raw data to the easyTRX.

All class B transceiver have in common, that they need an own GPS.

This is necessary because the normally existing GPS antennas deliver NMEA GPS data. This NMEA datas are generally not exactly enough in reference to their time-base. A typical class B AIS telegram takes 25ms. Within 1 ms the class B transceiver has to deliver his „beam“. In order that the sent telegrams are not overlapping, every sender has to keep an exact for sending. The date for sending has to be more accurate as the telegram. The date of sending is determined at ca. 100µs by the class B sender. This is only possible, when the sender gets the raw data from the GPS antenna and not NMEA data, which are only accurate to 1/10 s. This is the reason. For a reliable operation GPS datas on a µs base are needed. With the explanation above you need 2 GPS antennas. One with NMEA data for your chartplotter and one for the easyTRX.

The easyTRX is a class B CS AIS transceiver. The easyTRX is conform to the current class B norms and certified by the BSH. All by the BSH certified transceivers are mostly similar.

The reason for this is, because they have to fulfill the norms, which are very detailed and strict. The norms are defining nearly everything beginning form the type of the case over EMV-values, powersupply, synchronistaion of the AIS radio network, channel access, channel state, displays, procedure types, and actions for the suppression of neighbour-channels, broadcasting power until the shoe-size oft he user.

This is why the devices are only different in the design, the graphical user-interface for programming the MMSI and the basic applications for displaying AIS. Different are mostly the flexible factors like the detail grade of the manual, the completeness of the connection cables, and necessary accessoirs and also the availability of useful accessory devices splitters with class B capability and combined VHF/GPS antennas. Also the service of the manufacturer which ours is the best one! All class B transceiver have in common, that they need an own GPS. This is necessary because the normally existing GPS antennas deliver NMEA GPS data. This NMEA datas are generally not exactly enough in reference to their time-base. A typical class B AIS telegram takes 25ms. Within 1 ms the class B transceiver hast o deliver his „beam“. In order that sent telegrams are not overlapping, every sender has to keep an exact for sending. The date for sending has to be more accurate as the telegram. The date of sending is determined at ca. 100µs by the class B sender. This is only possible, when the sender gets the raw data from the GPS antenna and not NMEA data, which are only accurate to 1/10 s. This is the reason.

You cannot put both, the easyTRX with a data rate of 38400 Baud and the GPS NMEA data with 4800 Baud, to one interface of the C70. In your case of usage you will need a multiplexer, which increases the 4800 Baud of the NMEA GPS datas to 38400 Baud.

If you want to operate a dsc-radio station or an AIS-transponder easyTRX on a boat, you need a registration for this radio-station. You get the registration from the federal network agency. The federal network agency will allocate your radio-station a MMSI-number, which you program into the easyTRX. If you da already have a MMSI and additional you want to operate an easyTRX, you must send a notification of change to the federal network agency. You program your existing MMSI into the easyTRX.

-Under this link you get more information: Bundesnetzagentur Aussenstelle Hamburg Sachsenstr. 12 und 14 20097 Hamburg Tel.: 040 23655-0 Fax: 040 23655-182 E-Mail: [email protected]   www.bundesnetzagentur.de

If you want to operate a dsc-radio station or an AIS-transponder easyTRX on a boat, you need a registration for this radio-station. You get the registration from the federal network agency. The federal network agency will allocate your radio-station a MMSI-number, which you program into the easyTRX. If you already have a MMSI and additional you want to operate an easyTRX, you must send a notification of change to the federal network agency. You program your existing MMSI into the easyTRX.

-Under this link you get more information: Bundesnetzagentur Aussenstelle Hamburg Sachsenstr. 12 und 14 20097 Hamburg Tel.: 040 23655-0 Fax: 040 23655-182 E-Mail: [email protected] http://www.bundesnetzagentur.de

No, you can install an easyTRX on your boat. A certificate of marine communications is not necessary for the AIS-transponder.

At first a general information: The easyTRX is “dull” in regard to data evaluation on the PC.

This evaluation is not done by the easyTRX itself, but by the PC or plotter. The easyTRX is only very complex regard to high frequency data reception. There are ca. 45 different navisoftwares world wide. Unfortunately it can not basically be said if your own C-Map version is compatible to AIS or not. Generally C-Map is compatible to AIS since two years.

Please check out www.c-map.com to ask whether your Version is compatible to AIS.

The AIS software, which is delivered with every easyTRX, programs your specific ship data in the easyTRX, so that they could be send. Furthermore, you can display targets in a certain area around you on a radar-like screen. There you can not see marine charts, but this radar-like screen.

Yes, the easyTRX works completely independent. As long as the easyTRX is switched on, it receives and sends data.

The so called “CPA Alarm” works through the interpretation of the received data, either from the plotter or the PC.

Yes and No. AIS is able to reiceve weather information, but these information are only send from one point of the world: the Saint Lawrence River, USA. Therefor there is no reception of weather information by AIS.

In average 4W.

No, the easyTRX always sends data. If your ship moves it sends every 30s., if it is anchored, every 3 minutes.

Yes it is.

This error is probably due to your plotter or PC software.

The easyTRX always sends the own position in a NMEA-Sentence, too. It is the sentence “VDO” (own AIS position). The other targets (ships) are sent with the sentence “VDM” to the plotter/PC. We guess that the plotter or PC software you use does not make a difference between VDO and VDM. An update could help here. The easyTRX can not suppress the VDO, because it is mandatory.

The easyTRX sends, like all other CLASS B units – position data and static data. It is mandatory when and how often these data has to be transmitted. In that point, there is no difference in Class B units.

Position data (Msg.-type 18) are sent every 30 sec if you are faster that 2 kn, else it is sent every 3 min. The static data (Msg.-type 24) are sent every 6 min. It is always exactly 6 min; more often is forbidden. After switching on, it could last up to 6 min until the static data are visible to other ships.

Please make sure you entered your statistic data with the Link2AIS software. If you did not do so, the Msg.24 is “empty”. (You only have to program the easyTRX once; then the data remains in the unit).

Another reason for not being seen could be your antenna. All AIS Class B have a transmission power of 2 W. It could be that your antenna cable is too long with a too bad quality or your antenna is mounted to deep. The higher the antenna is mounted, the bigger is their range.

The 12 V alarm sounds, when the voltage while sending is under 9,6 V. While sending, the easyTRX needs about 2 A power. Please make sure that your cable is not too long and has an adequate width.

You have to check one thing: Are all the customized data set in the Link2AIS software (Static Data Configuration)? Only if these data are set, the data can be transmitted. If the dealer sets the MMSI, the rest of the data might still miss and therefore will not be transmitted.

What you detect is totally o.k. and normal.

This is due to the difference between dynamic and static data. In the AIS radio net there are at the moment 24 different message types existing. The dynamic data of a class B AIS transmitter are sent with the telegram type 18. The static data of a class B AIS transmitter are sent with the telegram type 24. Each telegram, not depending on type length is 25ms. All telegrams are checked internally in the easyTRX, if all the data are received completely. If the checksum is not correct, the telegram won´t appear on the plotter screen.

Dynamic data type 18: If the pleasure vessel is faster than 0,1kn the transmission cycle time is 30sec. If the pleasure vessel is at anchor the transmission cycle time is 3min. Dynamic Data content: MMSI, SOG, Position Lat and Long, COG, UTC and TH.

Static data type 24: Not depending on the speed or the vessel, the static data transmission cycle time is 6 min. Static data content: MMSI, call sign, ships name, ship type (37= pleasure boat), dimensions of the ship, pos of the GPS antenna on the ship.

Now the situation is the following: Let’s say the customer gets the first input of dynamic data at 8nm distance. It might take max 6min from that point that the other Class B ship sends out a static data. If there are interferences the customer might not get the static data once. So he has to wait again for further 6min. With the dynamic data, a “lost” of one telegram is not so dramatic, because these are repeated every 30s. With the static data, a “lost” of one telegram is suboptimal, because these are repeated every 6min.

The error originates from the coast guard’s software.

The standard of AIS Class B for pleasure boats has been realized in 2006. We know that some older AIS Class A ships have problems with the Class B transmissions. It is only a matter of time until the older Class A update their softwares. If the coast guards ask you again about that problem, you can show them the certifications number which you can find in the manual. It is the number BSH / 46162 / 4320638 / 07 and says that the unit is legal.

The easyTRX housing is isolated, whereas the VHF and the GPS antenna shield is connected to battery minus.
RS232 is referenced to battery minus.
RS422 is isolated.

If you changed the antenna and the fault is still appearing, the problem might be the plotter:

You have to know that the easyTRX is sending failure messages regularly. There is “flag” in each failure message. This flag shows whether there is a real failure or only the regularly “internal check” and the report about it.

If the flag in the failure message is “V”, means system checked, no failure -=>v for verified.

If the flag in the failure message is “A”, means failure a=> acknowledges, means real failure existing.

The plotter does not interpret the “failure flags” in a correct way. It might receive failure messages and if there are a lot of messages (incl. AIS messages) it just displays the failures, which are no failures indeed, just to get rid of them to get free space.

We know it from the Raymarine plotter E120 and with the newest plotter software this problem disappeared. Please check out if you have the latest software variant firmware update.

Another possibility to check it is if the green LED on the easyTRX is on, there is no “real failure”. It is a misinterpretation of the plotter!!

Also at the easyTRX Link to AIS software there is in expert mode the possibility to see the alarm log. There you can see whether the alarm is a real one, with “A” or just the confirmation with “V” that there is no alarm. Please check this out.

The first thing to check is if you set the dimensions A, B, C, D in the easyTRX software. Some plotters need that to show the ship on screen.

There could be some more reason:
The Raymarine C70 and C120 have an old software that is not able to decode Class B AIS (pleasure boats) messages. They only show Class A AIS (commercial vessels).

Please do an update to version 4.29. This is the software which is able to display Class B AIS!
When you turn on the easyTRX and the green light is on (yellow, red and blue LED must be off!), then you have to wait up to 3-4 min until the easyTRX transmits!

This mode is called “silent mode”. Connection as follows: from the machine run out 4 harnesses. 1x Power, 1x data for plotters, 1x data for PC, 1x external switch. The Wire for the external switch is 2-pole, black and purple. If the wires are shorted, i.e. are connected via a switch, then the easyTRX in pure reception mode. With this switch, then a switch between transmit / receive mode (switch is not closed) and closed pure reception operation (shaded) is possible.