Friday, September 12, 2014

VHFs, simple, right?

I wish.  I always seem to get the really weird-ass problems, probably because I try different things - and pay the price....

In keeping with my Simrad theme, I decided a long time back to use their new RS35 VHFs with remote hand sets.  They are native N2K so no clumsy adapters, and include an AIS reciever which I figured made for a nice backup in case the main AIS crapped out.  And how hard can it be to make the basic VHF functions work, right?

Well, what a train wreck it turned out to be.  As might be expected with a new product, by the time we got on the boat Simrad had release a software update for the RS35.  Usually this would be no big deal, but this particular update required that the radios be returned to the factory to have the update applied.  We had time, so shipped them back for updating.  What was supposed to be a week turned into two, then into three, but eventually we got them back and reinstalled them.

For anyone who has used N2K, you have probably heard about Instancing.  This is simply assigning an Instance number to any devices on the network that can produce the same data, and provides a way to distinguish who's talking.  Think of two people in a room talking at the same time.  If you couldn't distinguish their voices, you would have a heck of a time following either conversation.  On the other hand if you can distinguish their voices, you can pick which to listen to and ignore the other.  A device's Instance Number gives it a unique voice so you can decide who to listen to.

Because the RS35 is also an AIS receiver, it would be the second one and needs to be given a unique instance number.  Plus, I have tow RS35s, so they need to be further distinguished from each other.  That's where the problems began.  First, the NSO chart plotter which has the ability to assign instance numbers to any device, reported that the VHF rejected the change.  But when you would then look at the VHF on the network, it had correctly taken on the new Instance Number.  That's a pretty embarrassing bug when both products are from the same company.

But then things got really weird.  Listing all the devices on the network, the VHFs were showing up twice, and a bunch of the information about them was scrambled.  But they seemed to work, and running Maretron's Instancing Test which checks for different devices talking on the network with the same instance number, wasn't reporting any errors.

And then things got really, really weird.  While I was trying the radios, one of them went dark like it had been turned off.  I checked the on/off knob. checked the breaker, and checked for power at the terminals and all seemed fine.  But this VHF was dead as a stone.  I chalked it up to a freak issue and left the other radio on over night.  The next morning when I can in, Chris told me the second radio was dead when he got there.

At this point I had lost all confidence in these VHFs and suggested we dump them and switch to tried and true ICOM VHFs, even thought they would require extra adapters, etc.  That was the plan, but I later got convinced to try them one more time since the first replacement was already on it's way.  I agreed with the provision any other issues would be the third strike.  Well, on our Catalina trip guess what happened?  A third radio went dark and became completely dead.  So Simrad VHFs are now dead to me, quite literally.  If anyone is considering one of these VHFs, don't walk away, run.

I now have an ICOM M506 as an experiment to see how it works.  It has similar functionality with N2K connectivity and an AIS receiver.  It hasn't gone dead on me, so that's the good news, but I'm not convinced it's going to work acceptably.  Once again, vendors haven't done Instancing properly.  In the case of the ICOM, you can't change the Instance number at all.  And you can't tell it to not broadcast it's AIS info on the N2K network.  I'm pretty sure it's going to cause problems with my chart plotter and nav software when they try to display indistinguishable AIS info from three different receivers, two of which use the same Instance Number.  If I doesn't work, I'll probably just fall back to the same model radio without the AIS option (they offer it both ways).  I'd be giving up the backup AIS receiver, but all these vendors seem too retarded to build anything that meets the specs and works in anything other than a rudimentary network.  NMEA makes a lot of noise about how you should only buy Certified products.  Well, these are all certified products and the most basic functions are not implemented properly.  It's no wonder N2K has a bad reputation in some circles.

Or maybe I just don't understand how this stuff is supposed to work?  If only the spec weren't super double top secret and didn't cost $3000 to get a copy, I could actually find out.  Maybe if it's correct operation were well known instead of a secret it would work better.  I'm glad it's Friday, 'cause I've kinda had it....

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