Question Regarding Standard Horizon VHF Matrix AIS GX2100

[wingssail]

Hey guys, I'm just installing the GX2000 and got it all connected to my WM Class B AIS transponder and also to my Lowrance GPS (this is how I beat the 4800 vs 38200 issue, two inputs, two baud rates.) Works fine. The screen is small but the information is there and readable.

Now, what the heck do these GX2000 AIS settings of "Activation Range", "CPA Alarm (distance)", and "TCPA Alarm (Time)" actually mean? The manual is not clear.

I've been using my AIS with OpenCPN for over a year, it works great, and the options make sense. But I'd like to use the GX2000 as an AIS Monitor and alarm when the PC is shut down. How do I make it tell me that a vessel will be, say, within 1 mile within the next 30 minutes?

[s/v Jedi]

Originally Posted by wingssail

Now, what the heck do these GX2000 AIS settings of "Activation Range", "CPA Alarm (distance)", and "TCPA Alarm (Time)" actually mean? The manual is not clear.

Okay, it's not very difficult:

1. Activation range - the circle around you in which you want to check targets for collision course. All targets outside this circle are ignored by the alarm routines.

2. CPA alarm - CPA stands for Closest Point of Approach... IN THE FUTURE. The system will try to forecast how close those targets will come to you at some point in the future. This is where you can tell your system to ignore targets that stay at least 1 nm away or whatever value you enter.

3. TCPA alarm - Time to CPA. This is the forecasted time it takes a target to arrive at the CPA of that target. If the system calculates that it takes another 30 minutes, you might not want to hear that alarm yet. You could set it at 10 minutes for example.

Some systems go way beyond these possibilities. I have used AIS screens that show red-shaded areas on a radar-like screens with targets. Those red-shaded areas are the areas I should avoid to prevent collision or CPA alarms. This makes it very easy to steer to safety in tight situations. It write this here so that you understand that there is much more than these three alarm settings in the world of AIS

ciao!
Nick.

[wingssail]

Originally Posted by s/v Jedi

Okay, it's not very difficult:

1. Activation range - the circle around you in which you want to check targets for collision course. All targets outside this circle are ignored by the alarm routines.

2. CPA alarm - CPA stands for Closest Point of Approach... IN THE FUTURE. The system will try to forecast how close those targets will come to you at some point in the future. This is where you can tell your system to ignore targets that stay at least 1 nm away or whatever value you enter.

3. TCPA alarm - Time to CPA. This is the forecasted time it takes a target to arrive at the CPA of that target. If the system calculates that it takes another 30 minutes, you might not want to hear that alarm yet. You could set it at 10 minutes for example.

Some systems go way beyond these possibilities. I have used AIS screens that show red-shaded areas on a radar-like screens with targets. Those red-shaded areas are the areas I should avoid to prevent collision or CPA alarms. This makes it very easy to steer to safety in tight situations. It write this here so that you understand that there is much more than these three alarm settings in the world of AIS

ciao!
Nick.

Thanks Nick, that's terrific. Now:

4. How do I kill the Alarm when it sounds (while I deal with the situation) because going to the setting screen is pretty hard while the radio is constantly switching back to the ais screen.

5. Can I make it ignore anchored or stationart targets?

6. Why are the CPA and TCPA alarms separately activated. One does not make sense without the other?

Sorry for asking you these questions, I am having no luck emailing SH Technical support.

Fred Roswold, SV Wings, Cape Town

[barnakiel]

Originally Posted by wingssail

(...)

4. How do I kill the Alarm when it sounds (while I deal with the situation) because going to the setting screen is pretty hard while the radio is constantly switching back to the ais screen.

(...)

This is reported as a nasty glitch. Perhaps someone knows more.

b.

[s/v Jedi]

Originally Posted by wingssail

Thanks Nick, that's terrific. Now:

Ai Fred, I don't have that radio and wouldn't know the answers. I could answer your earlier questions because they are standard for all AIS equipment.

But for the separate CPA and TCPA alarm: they are not separate. They are two parameters for the single alarm. It works using this formula:

If (CPA <= CPAsetting) And (TCPA <= TCPAsetting) Then
Alarm!
EndIf

Hope that makes sense to you

ciao!
Nick.

[s/v 'Faith']

I have read this thread 2x now, and am more confused then before.

Can a SH 2150 be connected to both a Garmin 540s to display AIS data, AND a ST-2000 autopilot (without a multiplexer?)

I do not care if the DSC works.

Seems to me like the radio would need both an input and output (2 0183 NEMA ports right?)... and the autopilot would need one too?

Can you connect more then out devise to a NEMA output? (like the autopilot AND the SH 2150?)

Can anyone help me figure this out?

[Dustymc]

Originally Posted by s/v 'Faith'

Can a SH 2150 be connected to both a Garmin 540s to display AIS data

My GX2100 happily talks to my 740s and vice-versa. Close enuf? Dat's all I know....

[colemj]

I'm confused why you would want AIS data on your autopilot. I don't know of any pilot that even accepts AIS sentences, let alone a tiller pilot with no external display.

But you can connect the AIS output to multiple listeners without a multiplexer, so if you want to hook it to your autopilot it will be fine (but may not be useful). That's a general rule, but the way - one talker (output) to multiple listeners (input) - and not just for the AIS.

The only input on the radio is the GPS receive line. All other lines are outputs. There are 4 wires for communications with this radio - GPS in, DSC out, AIS out and common. You can get the manual from their website and it explains the wiring and how to hook it up.

Mark

[wingssail]

Originally Posted by barnakiel

The alarm function there is very good if at times I wish there were a one button option to calm it (as far as I could get from the manual, you have to go thru a sequence to turn it off once it starts buzzing).

The screenie is ok with few objects but it IS a small screen. If you are after a graphical representation of what is coming at you then either get a nice external screen (e.g. the new i70 from Ray) or get a standalone AIS unit with decent screen size (e.g. the new color Vesper or the older color Simrad).

So, if you want the warning beep then you get one but the screen IS small.

b.

barnakiel, Do you have personal experiences (or anyone else out there) in which you had re-occuring alarms which you had trouble stopping, and if so, how did you deal with it?

Fred

[capecuddy]

You need to set up the processing regions and alarm radii properly.

[colemj]

Also, if you programmed it with a MMSI number and do not have a GPS position input to it, the alarm will go off at regular intervals. There does not seem to be a way to stop this other than providing GPS input or not programming the MMSI in the first place.

Mark

[Bob on OTTER]

SH has a market for the AIS/internal GPS capability....with output for interface. seems perfect combo...have to assume they are working that.

[surfmachine]

Hi, I have connected up my new gx2150 to my 2008 raymarine A50
chartplotter, it reads the gps input but will not show any ais input
or display???

Do you know if the a50, running V0.04 software is able to display the
gx2150 ais data? I am not sure if it can read the VDM sentences used in NMEA by the AIS on the matriz output???
Does it need a software upgrade??

I have config the gx2150 to 38400 bps
I have config the a50 to output 38400 bps
I have cofig the a50 to sgow ais overlays, but it still has X through
the AIS symbol up the top right hand side even though the radio shows
ais symbols within the a50 range??

What have I done wrong???
I have looked on the SH site and downloaded the connection diagrams.

Thanks from Keith.

[Svsilvergirl]

I don't know anything about the raymarine unit you have. My garmin 740 was plug and play. But the tech guys at SH were awesome. I called them before I bought the radio , because the garmin 740s wasn't listed in their wiring diagrams. The tech actually drew me a picture and emailed me all the settings for both units , and added them to their website afterwards. You will prolly have better luck getting some answers from SH than raymarine . Just saying. A friend of mine had a fairly new complete raymarine system , C120 , autopilot, ais transponder , all the wind and depth stuff , a d he has had terrible tech support thru them. Guess one person actually told him he must be having trouble reading , as the answers are clearly in the manuals.

[surfmachine]

Thanks silvergirl, exactly my experience as well with Raymarine.
I suspect that the A50 cant read the VDM sentences.
I am updating the software on the chartplotter tomorrow.
Have sent of the question to SH as well.
Cheers from Keith.