Friday, December 28, 2012

Beginners Guide to Raymarine's Seatalk and Derivatives

Seatalk is Raymarine's proprietary communication "language" for interconnecting Raymarine instruments. Unfortunately Raymarine keeps the technical details of Seatalk secret and so the nitty critty of the system often has to be reversed engineered if designing something to work with Ray's different seatalk buses. However, most of you out there just want a plug and play system and I can say that Raymarine has done a pretty good job of that.

Raymarine has produced four communications protocols featuring SeaTalk as the root of the protocol's name. These include:
  • SeaTalk (also referred to as SeaTalk1 or first generation SeaTalk)
  • SeaTalk2
  • SeaTalkng
  • SeaTalkhs

Seatalk to nmea0183 and RS232

Seatalk is the same as seatalk1. Ray just added the 1 after developing other more modern buses that they called seatalk2, seatalk hs and seatalk ng. Seatalk1 is ray's propriety version of nmea 0183. Seatalk1 is readily able to be converted to nmea 0183. Raymarine supply an accessory (Part #E85001) for converting Seatalk to NMEA 0183. Also, ShipModul's and Brookhouse's MUXes also convert Seatalk to NMEA 0183. Alternatively, if you have the ST60 repeater, you will find a NMEA output on the device which can connect directly to a SOB COM port.

Seatalk which is often referred to now, as seatalk1, is a multi-talker, multi-listener approach using serial data at low data rates (4.8Kbps). Compare that to nmea 0183 which is predominately a single talker, multi listener unless one uses a multiplexer.

The network used proprietary cables and connectors that were designed for the marine environment. The connectors are three pin molded and incorporate 1/8” automotive spades as mating elements. 

Seatalk cable
The network could be implemented as either a simple daisy chain structure or the more robust approaches of backbone, spur or star design.

SeaTalk uses three wires, connected in parallel to all devices on the bus:
  1.  +12V    Supply, red
  2.  GND    Supply, grey
  3.  Data     Serial Data, yellow
There is no master on the bus. Every device has equal rights and is allowed to talk as soon as it recognizes the bus to be idle (+12V for at least 10/4800 seconds). Low priority messages use a longer or randomly selected idle-bus-waiting-time. This allows messages from other devices with a higher priority to be transmitted first. The different waiting times of all devices make data collisions (two or more devices start talking at exactly the same moment) very rare.

Unlike the Seatalk2 and Seatalk ng communications protocols, Seatalk communications protocol does not feature termination. Any Seatalk instruments and instruments or autopilot components featuring a 1st generation Seatalk interface which does not have a Seatalk ng interface (ex. ST40/60+ Instrument Displays, ST6001, etc.) can be interfaced to one another, in any order, using standard Seatalk cable. Seatalk cables can be joined using a Seatalk Junction Block, splices, marine grade terminal strips, or R55006 Seatalk Auxiliary Junction Boxes. This method of interfacing is referred to as a Seatalk bus. The Seatalk bus will typically be powered via a Seatalk Auxiliary Junction Box or via a Seatalk power cable which has been connected to one of the Seatalk devices.

Seatalk hs is raymarines high speed version of ethernet. It is plug and play.

By using SeaTalk hs networking, you can instantly transfer radar, chartplotter, fishfinder, thermal imaging and navigation functions. Configuring your system is a simple as determining which SeaTalk hs devices you'd like to have (chart, radar, sonar, video) and where you would like to see them.
The most basic system may consist of a C Series Widescreen or an E Series Widescreen with a DSM30, DSM300 or a radar. The components are all auto sensing, there is no complicated setup required. Simply plug them in.

E series integrates nmea 0183, 2000 and seatalk hs
Raymarine E-Series can input/output data via good old NMEA 0183, Seatalk (Ray’s proprietary improvement on 0183), Seatalk2 (sort of NMEA 2000 but seatalk ng is the bus that mimic's nmea 2000), and Seatalk HS (actually Ethernet).  Plus the E’s (and C’s) do something called data bridging where they take data from one bus and put it onto another bus.

Raymarine has network switches when working between 3 to 8 devices. They are.......
  1. The new HS-5 Seatalk hs Network Switch which has five ports
  2. Seatalk hs Network Switch which has 8 ports.

The following devices have Seatalk hs connections and can be easily connected together via the Seatalk hs network switch and Seatalk hs network cables:

  1. New e Series Multifunction Displays
  2. New c Series Multifunction Displays
  3. C Series Widescreen Multifunction Display
  4. E Series Widescreen Multifunction Displays
  5. G Series Navigation
  6. E Series Classic legacy Display 
  7. T Series Thermal Cameras
  8. DSM30 and DSM300 Fishfinders
  9. Super HD and HD Digital Open Array Radar
  10. Digital Radome Radar

Seatalk 2
Seatalk 2 is a five conductor system that has some N2K functionality. This network does require terminators at each end.

Seatalk 2 network 
and here is the comparison of the different network cables below.....
seatalk1 cable

 Provided you do not want to connect to NMEA2000, you can connect a Seatalkng system to Seatalk(1) using a suitable Seatalkng bridging product (such as an ST70 instrument) and adapter cables to connect the two systems.
If you intend doing this, note that:
You can connect a single Seatalk(1) network to Seatalkng using an adapter cable and one bridging product (e.g. ST70 instrument).
You can connect two separate Seatalk(1) networks to SeaTalkng using different adapter cables and bridging products (e.g. ST70 instruments), but the two Seatalk(1) networks must NOT be connected together. See below for the diagrams
Seatalk2 cable

Seatalk 2 whilst is not plug compatible with NMEA2000 or SeatalkNG, adapter cables are available. Raymarine A06048 is the part number for seatalk ng to seatalk2 adapter cable. (not shown).
Any data available on the SeaTalk2 network will then be available on the SeaTalk NG network. Only one connection is needed per network.
This adapter enables an existing instrument network, using the SeaTalk2 5-pin connectors, to interface with a SeaTalk NG network.
*Note that this cable cannot be used to connect a SeatalkNG network to the Seatalk2 port on the back of a Raymarine E-Series display. Use cable A06061 for that purpose.

Older Style of Seatalk hs cable

Raymarine’s current generation of ethernet cables replaces the RJ45 connector (seen to the left) with a waterproof vibration tolerant twist pin connector that is designed for the marine environment.
The new RayNet (F) to RayNet (F) network cable can be used to daisy-chain 2 adjacent RayNet devices together. It is also useful for joining two adjacent HS-5 Network Switches together on larger systems where multiple switches are necessary.

Rayamrine has a number of adapter cables which most are to adapt the older RJ45 with the newer Raynet cable. They can be seen here

An NMEA standard for the transfer of NMEA 2000 messages using an Ethernet protocol is being developed that will be called OneNet.

Correct method seatalk1 to seatalk ng via ST70 instrument
No ST70 for bridge
Do not link different seatalk1 networks together.
Seatalk ng

SeaTalkng is an interconnection bus for Raymarine products, and comprises a main
backbone to which Raymarine products are connected via spur cables.
Seatalk ng is basically NMEA 2000 and can be connected to a NMEA 2000 network via an adapter cable.
SeaTalkng comprises a single backbone terminated with two terminators, one at each end. Spur cables connect the backbone to individual Seatalkng products.
Small diameter cable connectors are used throughout the system, to make installation easier. Cables and connectors are color-coded to reduce the likelihood of misconnection.
A wide range of different cable lengths provides flexibility and obviates the need for cutting and splicing cables.
Three-way, five-way and in-line connection pieces are available to connect cables, to
deploy Seatalkng as required.

Typical seatalk ng network,

One of the things I like with the raymarine seatalk ng is the 5 way connector blocks. Something I wish NMEA 2000 would have. NMEA 2000 also has this and be seen here.
Plan the route of the Seatalk ng backbone so that it runs as close as is practicable to the intended location of each Seatalk ng product, to keep spur lengths to a minimum.
Products connect to the backbone via spur cables. Spurs connect to the backbone via either a Seatalk ng T-Piece or a Seatalkng 5-Way Connector

Seatalk (sic) has a number of adapter cables, of which one is the seatalk ng to NMEA 2000 adapter cable. Part number A06045 for the female cable and A06046 for the male cable.
You can see a range from rayamrine, of the adapter cables here.

Raymarine with Wifi and Bluetooth
This is still in it's infancy, but is now working. It can only get better from here. There iOS app has been released and can be viewed here. I wonder if it will work with an iMux instead of their e-series display WiFi?

RayControl transforms your tablet into a full function Raymarine MFD. Remotely control and view electronic charting, sonar, radar, and even thermal night vision, right from your tablet.

RayControl emulates Raymarine MFD’s with touch screen interaction and a virtual slide out MFD keyboard. The slide out virtual keyboard gives you control of all MFD functions and the virtual uni-controller allows you rotate through menus and adjustments effortlessly.

Take a look....

Perhaps in the not to distant future an iMux will no longer be required as manufacturers integrate wifi and bluetooth into their products. I look forward to that, but in the mean time, the cheapest option for someone who has already invested heavily in existing technology is a Wifi seatalk/nmea multiplexer.
Whether you use Navionics or iNavX on your iPad, you have to get the various Seatalk output data from your instruments, GPS, AIS into a format that can be understood by either of those programs. That is exactly what you have to do to get the same information into an onboard computer. Typically, this is accomplished by a multiplexer which is spliced into the Seatalk network. Most of the data comes at a slow baud rate, but the data from an AIS is at a much faster rate. The multiplexer takes all of these data streams and sorts them out and sends them in a controlled output to the computer or if WiFi capable, to your iThing. But now, with MFD's having WiFi integrated, it takes the hassle out of setting up a WiFi multiplexer. Also, it is one less device to purchase, to get WiFi   Looking at the video, RayControl also has some high bandwidth data displayed on your iThing. I'm impressed, and wonder what the other big manufacturers will bring to the market.
One last question. Does the new WiFi enabled e-series display integrate with iNavX for the data? I'm not expecting the chart to come across, but basic nmea 0183 sentences. Perhaps a reader will let us know.

Tuesday, December 25, 2012

Replaceing Sanitation Hose

Some of you may have experienced the "smelly" boat syndrome, and a lot of the time this often points to the sanitation hose which is permeating the smell, from the contents inside the hose.

Analysis and Design
When sanitation system odors end up on the wrong side of the hoses and tanks that are designed to contain them, the most frequent analysis is, “they are permeated” and a lot of the experts call for wholesale hose replacement. In fact, while this may ultimately be necessary, it’s often a case of addressing the symptom rather than the cause. If the hoses are replaced and the design is flawed, then it’s likely the new hoses will, once again, fail or permeate prematurely. (see avoiding sanitation woes)

How do you test for permeated hose? Once you have eliminated all other sources for the odour, take a flannel and soak it in hot water. Ring it out and drape over the suspect hose for a few minutes. Then take the flannel and place in a zip lock bag and take outside to fresh air. Open the zip lock bag and smell. If you smell sewage, then you hose is permeated.

Before I begin with my solution(s), I just want to recap some of the salient points for a healthy head/holding tank systems and things you should look at on your boats sanitation system. By ensuring these procedures and implementing the points below on design layout, they can greatly reduce the the permeated hose problem.

  • Rinse the holding tank out before layup and after every pump out. Lots of H2O helps with cleaning the remainder of the "solids" which tend to fall to the bottom of the tank and build up.
  • If the holding tank has an inspection port, use that to wash down the sides of the tank; but watch for splatter back!!
  • What sort of tank should I have? I prefer polyethylene tanks. The holding tank in many boats is constructed of low density polyethylene, heat welded from flat sheet with polyethylene fittings. Not much can go wrong as polyethylene does not corrode, is impervious to odour and has great impact resistance. Fiberglass would be my second choice. Metal tanks are a poor choice due to corrosion.
  • Next step is to check the other components, Y valve,  macerator pump, hoses, hose clamps, tightness of joints, and vent line. Two outlets can prevent the need for a Y valve.
  • Flow into the tank from the head should be on top of the tank This will depend on your location of the tank, but if attached to the side, slosh from a boat heeling can back flow down the delivery hose and becomes the standing waste inside the hose. It also allows you to disconnect the hoses from the fittings if the tank is near full
  • The air vent should also be at the top of the tank and as large as practicably possible. Better still, put two vent hoses on to allow for a cross flow of air inside the tank. Aerobic bugs don't make the stink. Anaerobic bugs are responsible for the sewer smell.
  • The discharge line should also come from the top of the tank with a drop pipe. It is a poor design when the discharge is from a fitting at the bottom, or lower side of the tank and this leads to the hoses continuously submerged in effluent.
  • All hoses should run "down hill" or free draining to prevent standing effluent. When hoses are installed with large dips, low spots, or "u" shaped bends, effluent will settle in those bends, and it will be a challenge for even the best permeation resistant sanitation hose. These low spots can also lead to clogging.
This is all in an ideal world where holding tanks are designed properly, made from the correct material, plumbed correctly and the sanitation hose is the best money can buy. It doesn't happen. For instance, the holding tank location is often decided by what space is available. This often leads to hoses being plumbed that have residual effluent sitting in the hose. Sewage allowed to sit in the hose develops acids and gas that shorten its odor-free life. This is especially the case with white vinyl extra heavy-duty sanitation hose. Good installations are short and self- draining (no kinks, loops, or dips), with tight connections. Overtight fittings and clamping can damage hose ends, causing leaks and odorsOn my boat, the tank is higher than my head and the toilet has to pump up hill to the holding tank. Without extra flushing, this leads to effluent sitting in the hose. This also true of my discharge line.

To the left is a quick drawing of my head and the associated items in the sanitation circuit. There are a number of problems with my system.

  1. From the Macerator pump, it pumps up hill to the tank and if not flushed sufficiently, effluent stays in the line.
  2. The intake to the holding tank is on the side and should be on the top
  3. The outflow from the tank is from the bottom and therefore effluent will sit in the hose from the outlet to the Diaphragm Pump. A better option would be to have the outlet from the top of the holding tank with a drop pipe inside to the bottom for pick up 
So because of these poor designs in my sanitation system, effluent eventually permeates the sanitation hose and the boat becomes smelly. We all know how hard (and messy) it can be to change that sanitation hose and I have two ideas which may help with that. In addition, next time I'm at the boat, I will be changing the intake on the side of the holding tank, to the top of the tank.
First is to use barrel connectors made for alkathene (MDPE) pipe at each end of the sanitation hose. I use Hansen fittings. They may be called something different in your part of the world, but are commonly found in the farming industry and the marine industry. Our local chandler has sold these for years, but I never knew about the barrel fitting until I visited a more extensive store dedicated to Hanson fittings.

Barrel connector = big Nut
The picture to the left shows a barrel connector, which is the big nut in the middle. With one of these at each end and the sanitation hose between, one simply undoes the nut and pull the whole hose out to replace it.

Barrel nut  in the picture to the right undone. The big nut turns and slides back to allow the male end to slide out side ways.

Barrel nut in picture to the left showing the "O" ring which sits across the face of the opposite side for sealing.

Hanson makes hose tails, but I prefer to make my own.  They are good for tight/short runs of hose, Take a 1 and 1/4 inch nipple and turn one end down to 38mm. It just takes the threads off and I find the hose is a better fit and easier to get on and off. One and a half inch sanitation hose fits really good with a hose clip. One can also use the Hanson threaded end to pipe fitting (male straight coupling), by unscrewing the locking nut and discarding it, and slide the sanitation hose on and secure with hose clamps. If using Akathene pipe as suggested below, then you slide the pipe onto the tail and screw the nut over the pipe which cinches it down onto the tail of the fitting.
An image of one is shown below.

The other idea, of which I'm going to try out, is to use Alkathene (MDPE) pipe. This is a flexible pipe made from Polyethylene and I'll be using a medium density pipe. I'm trying it out because there is no info or data of anyone ever using this type of hose for boat sanitation hose. And yet it makes sense to me.This material is the same stuff that holding tanks are made from, and is used for effluent in our cities main sewer system and used by farmers for effluent discharge. While the stuff I will be using is designed for the transport of water, it is made from the same stuff the effluent MDPE pipe is, but at a size I can use. i.e. One and a half inches and one inch. (25 and 38mm)
Be aware that the pipe comes in low density and ranges through several levels to high density. It also comes in a range of sizes. The 40mm pipe and fittings are the one and a half inch  variety and in fact the inside of the pipe (ID) and  outside of the tails measure 38mm. This is the "real" size.

I'm setting this up so that, if I'm not happy with the Alkathene pipe, I can revert back to the sanitation hose without much ado. But I'm confident it will stop the permeation woes. The MDPE pipe is not as flexible as sanitation hose and if working with tight bends, you may have to use a Hanson elbow to get it around a corner. It is however, flexible , resistant to cracking, corrosion resistant  (some sanitation hose has a metal coil within the walls),chemical and abrasion resistant, excellent pressure resistance, easy to install, and more flexible than HDPE pipe. I have also used it around my farm, and it is so easy to connect, a child could do it.

While I would like the discharge line from the holding tank to come from the top of the tank, I'm going to leave it for the time being at the bottom of the tank. I'm hoping that by using MDPE pipe, which should be as good as any holding tank made from PE, then the issue of effluent in the line will not be a problem.

I also acknowledge that if you are using sanitation hose with barrel connectors each end, that they then in turn have to be connected to your devices. If your devices don't have a screw in fitting (like most PE holding tanks do),and has hose tails only, then one is faced with extra hose and hose clamps at each end. I think this is worth the extra "risk", and if the hose tail off the barrel connector is kept close to (<1/8 inch) from your device hose tail, then permeation at those points would be minimal.

Another change which I will also be doing is to put a barrel nut either side of the macerator pump, so that it is easy to take out should I need to work on it. It's in a tight location at the moment and difficult to get at the pump. These barrel nuts will make taking out the pump so much easier. I already have one on the discharge side of the macerator pump with a non return valve ( a joker valve, by which I machined  the barrel coupling to take), and a shut off valve so that if taking the pump out, I don't get a back flow from the hose leading up to the intake of the holding tank.

Below are some photo's showing the ease of the barrel nut disconnect, using both sanitation hose (in white) and Alkathene (MDPE) pipe in black.

You can place the nut of the barrel nut so that either stays on the removed hose section, or stays at the appliance fitting end.

Hope this will help for your next change of your sanitation hose. Below are some links that I thought might help.

A comparison of Trident Sanitation hose.
Need a custom made holding tank. In our city one of the plastic tank manufacturers will make custom tanks on any shape you give them. It seems Raritan also does this. Check out your local area; there may be someone who makes PE tanks.