Autohelm ST 7000 + Type 300 Computer + Raymarine ST60

[Richard10002]

Having worked perfectly, I have had to replace the Type 300 computer with a refurbished 2nd hand one.

Once all the wires were connected, there seems to be a problem with communications between the ST7000, and the ST60 stuff, and I regularly get lost fix and no position, even though Speed Over Ground and Course Over Ground are provided accurately, (checked against independent lowrance Plotter).

It's possible that I have wired up incorrectly so lets see if a simple question resolves things:

There are 3 Seatalk cables and only 2 sets of seatalk input on the computer, so I have put 2 seatalk cables in one input, and the other cable on its' own input.

I cant see how else to do it, as the 3 seatalk cables definitely came out of the computer, so there must have been 2 cables in one input.

Can I put 2 seatalk cables into 1 seatalk input on the computer?

Cheers

Richard

 

[hairbox]

My understanding of seatalk is that you daisy chain all the devices together from one output from the computer and data is then all talking the same protocol, and power is also delivered via seatalk so yes you can put all cables in one input.

 

[CSFenwick]

Hi Richard,

Just had my course computer out as well after the autopilot died last weekend. A bit of a bind when we're leaving to head south (ultimately Spain) this Saturday and has started a mad panic getting it back to Raymarine who’ve done a sterling job of fixing it and turning it straight around. It should be back tomorrow - fingers crossed!

Onto your problem, as hairbox says you can daisy-chain Sea-talk so you don’t need to bring them all back to the course computer. What are the 4 Sea-talk cable-sets from? On Orenda all the instruments are daisy-chained to the ST7000 control head and the Sea-talk from there is then the only one coming back to the course computer. Hence we only have one Sea-talk cable set actually connected at the computer.

The diagram below might help.

 

[Talulah]

Sounds like a corrupted data bus usually caused by insufficient power.
I suspect something is getting powered up off the seatalk network that should be having a stronger power source.
Usual thing to do is to disconnect different sections of the seatalk and see if things are still powered up the way you would expect them to be powered up.

 

[hightech]

Hi Richard,

You can hook up any number of wires to the T300 seatalk ports, you are just limited by the size of the holes!!

In practice, I wire up the pilot as one system, so seatalk out to the control unit(s) only, the connect just the black and yellow across to the instruments, that way you can power either on independently and the pilot load does not drop the instruments out. The only caveat to this it that you ar not feeding in NMEA to the T300 that you want to get to the instruments as when you power the pilot off the data will not get converted and passed on.

Regards
Geoff

 

[richardwatson]

You can bet its a compatibility issue. Their newer instruments like ST60 are not that compatible with their older equipment. After my Type 300 needed to be repaired, and subsequently replaced, my autopilot never worked 100% reliably again,and I ended up having to replace everything.
You should be able to get around 'lost fix' or 'no gps' by disconnecting the seatalk cabling between your plotter and autopilot, and wiring your gps directly to your plotter. You will lose cog, sog and track on the autohelm and true wind on the st60 but should still have a functioning plotter and a separate autopilot working just off its fluxgate compass.

 

[Richard10002]

[ QUOTE ]
You can bet its a compatibility issue.

[/ QUOTE ]

Possible, but hard to see when they've worked perfectly together since 2003. I've not made time to make use of some of the suggestions above, but I'll report back when I do.