Hello All
The SE8C manual states that each driver can drive a set of masts and each set of masts can have up to 4 different lamps or a multi-color search light blah blah blah.
What exactly is a head that they are talking about?
Springfield PA
A HEAD is a holder, if you will, for the lights. Generally there are three lamps or lights to a head. Green, yellow, and red. In signalling, these are called aspects. Green for proceed, yellow for approach, and red for stop. A HEAD can be in a different configuration or style depending on the railroad. One type is three lights in a vertical arrangement. Another could be like the PRR. Some western RR's use a searchlight type head. This has one bulb in it with a movable colored lens in front. When the lens changes, the color changes, but there are still only three aspects or colors in the one head with a single light.
Some signals have one head on a mast, some have two heads on a mast, and some have three heads on a mast. If a mast has more than one head, not all heads may have all three lights. Again it depends on the RR and the signal system.
The SE8C has eight drivers. Each driver can be called a 'plant' as Digitrax has done. Each driver can control four heads. Each head has three lights or LED's. Thus each SE8C can control 32 heads of three colors each.
If you are just getting started with signals, you may want to check out the following link about signals. It will give you some basic information, plus provide other links to signaling web sites that may help you.
http://mysite.verizon.net/vzescsbb/HO_MRR/Signals/Signals_getting_started1.html
Elmer.
The above is my opinion, from an active and experienced Model Railroader in N scale and HO since 1961.
(Modeling Freelance, Eastern US, HO scale, in 1962, with NCE DCC for locomotive control and a stand alone LocoNet for block detection and signals.) http://waynes-trains.com/ at home, and N scale at the Club.
If you're serious about signaling and want to understand the terminology used, I would also recommend Brian Solomon's book, "Railroad Signaling", published by MBI. ISBN 0-7603-1360-1
Jut to confuse things furhter, you do NOT need to group the 'heads' together as Digitrax shows. Each individual 'head' is individualy addressable. It might get complicated figuring out on which cable and in which orientation to palce a given signal head, but there is absolutely no logic or address combinations in the SE8C that requires them to be grouped together. You cna have 32 completely independent signal heads if you like. The 'C' in the name means Computer - you need a computer, with software like JMRI or RR&Co, to actually do the signal logic, ie, make this one red if that block is occupied. The SE8C simply maps stationary decoder addresses to a given set of LEDs. There's actually 2 addresses per signal head, meaning you can have 4 aspects, not just 3.
It seems a lot more complicated than it actually is. It might be simpler if it drove just a couple of signals but you'd be paying nearly as much and getting less, since the small microcontroller processors can drive so many outputs with just minor cheap logic attached. So it makes sense to build the board to drive as many signal heads as it can.
--Randy
Modeling the Reading Railroad in the 1950's
Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.
Oh and one place the manual relly messesd up on signal terminalogy compared to typical American practice - they callt he lower head on a two headed signal a dwarf. Typically if a dwarf signal is used, it owuld be as the siding signal, the one labeled as C in the SE8C manual. But it doesn't HAVE to be a dwarf signal, it can be up on a mast just like any other signal. On a simple protected turnout that they use for allt he examples, the lower head on the mast with two heads is often referred to as the 'diverging' signal.
Thanks for the feedback all
So if I understand it correctly the unit works differently when used from the PC vs throttle.
For instance If I use the example in the manual and throw switch address 257, 2 different lights respond.
throwing it will light the green led and extinguish the red led. Throwing 258 turns red and green off and lights yellow.
If it is different on the pc, where can i find a reference the the led addresses?
Thanks
Here's a link to our club's site
http://starr-mrc.org/
If you click on the word layout you will see what we'll be adding signaling to.
There is a 4 track main and plenty of sidings and yard area.
We intended on starting but quickly realized that a little more learning is in order with the SE8C module. At this point we're thinking it will take about 12-20 SE8's to do the job. Hopefully they come out with something a little more configurable in the future.
Hamltnblue Thanks for the feedback all So if I understand it correctly the unit works differently when used from the PC vs throttle. For instance If I use the example in the manual and throw switch address 257, 2 different lights respond. throwing it will light the green led and extinguish the red led. Throwing 258 turns red and green off and lights yellow. If it is different on the pc, where can i find a reference the the led addresses? Thanks
It should be no different with a PC. The thing with JMRI is is sort of insualtes you from the direct manipulation of all teh addresses but it should still work the same. In JMRI, signals attached to an SE8C are definted as LHxxx for Loconet signal Head. You have to create the table of entries for this. When you pick SE8C type signals, it has a space in each entry for the two addresses for each head. You cna then put an icon or a control on a panel and assign it to this LH and when you manipulate the signal or control, it will set the addresses T or C as appropriate to set the required indication.
It's sort of fun, actually, and now it makes me want to get one and add signals to my layout. However I just aquired an employee timetable for my line and my branch was TT&TO operated, not signaled.
After pulling my remaining hair out trying to understand the wiring of 4 heads on the same cable i finally found an article that explained it.
When you wire the heads the LED's of 2 heads share the same terminals for each color but have a different common. I was wondering how it could do it.
Turns out that the SE8C actually flashes the LED's on and off faster than the eye can see. It sets head 1 including common for an instant, then sets head 2 and the other common for an instant. Back and forth constantly. Pretty neat.
Often called "charlieplexing" in electronic circles: http://en.wikipedia.org/wiki/Charlieplexing
"More configurable"? The SE8C basically has NO configuration sinc eyou need the computer to do all the logic. Which some people seem to hate and go with devics that have built in logic like the Team Digital and CML units - but in the end those are MORE limited.
There is also the RR-CirKit Tower Controller and the 4ASD interface board. The wiring's a bit simpler but to end up with the 32 heads of an SE8C it will cost significantly more. 12-20 SE8C's? That's 384 - 640 signal heads. Not every turnout in a block needs individual protection. Multiple industry sidings would be tied to the signals at either end of the block they were located in, and would not have individual signals governing entry to the main. That's one place to save singals. Also don't make intermediate blocks too short, or every train will be spanning multiples.
Im familiar with multiplexing but never though they would have used it in this application. Good Stuff.
The board actually does have a built in configuration. The red green and yellow of each set will prioritize, at least with the controller. For instance there isn't an option noted to have red and yellow lit the same time. If you select one color it turns the others off.
Another thing I noticed while setting up is that the track power has to be energized for it to work even if you use an external power source. My DS100 isn't defaulted on. When I started the SE8 wouldn't respond to any commands or programming. Turning track power on fixed the issue.
Yes but I have yet to see a prototype signal that has the red and yellow both lit ont he same head! Yellow over reed, or flashing yellow over red - two different heads. Of course now someone will promptly post a picture that shows two colors lit on the same head.
Agreed.
On another note can the PR3 be configured to talk directly with the SE8 without a main controller? I'd like to run it at the desktop PC to experiment and play some.
Yes, it should - you need to enable the termination on the PR3, as any loconet needs to be terminated. Any Digitrax command sttion does this, and the PR3 and Locobuffer can be configured to provide termination. Also the BDL168 can be configured for termination. In JMRI there is an option to switch the PR3 mode from standalone to interface. I'm not sure what is needed to drive the SE8C - but I suspect it actually needs to be set to standalone and then you need to use the track power option to turn on 'track power' - when I do that on my test/programmign track it allows me to activate sounds with a JMRI throttle, and in some cases actually drive the train a little bit before the current limit is exceeded. So you probably need to conenct up everything - the external power for the SE8C, and the track power to the PR3's track connections. Probably a loconet cable as well - you can also program the SE8C via JMRI that way. You can fully test everythign withotu ANY devices, usign the Loconet SImulator interface in JMRI, but you will then need to have an actual SE8C addressed exactly as defined in the tables to then switch to the 'live' Loconet and expect it to work.
If you set OpSw14 closed on the SE8C it will respond to the commands on Loconet, not track power, and so shouldn't need track power turned on. Or it this is a standalone signalling system, you cna set the DCS100 to start up with track power on automatically. If it's not connected tot he track, there's really no danger in this - I don;t recommend having track power turn on at power up if it actually is powering the runnign track - that way there is no unexpected movement of locos left on the track.
No problems configuring the SE8 in stand alone but actually controlling the outputs is an issue.
I suspect it is the track power control or lack of it.
I tried the layout power command as well as the track power button on the throttle but it reverts back to off.
The DS100 is not available at the pc.
I'm confused - the power issues are with trying to use the PR3 standalone? Make sure it is in the correct mode, it should be in standalone not MS100 mode. If it's turning the power off immediately there might be too much draw on the track power, it can't really supply enough power to say move a loco, but it can activate sounds in sound decoders. Do you have the aux power connected to the SE8C? No way can the PR3 supply enough power to run an SE8C via the track connections. Do not plug a throttle into all this, the PR3 isn't really a command station. You should just have the SE8C connected to the PR3 via the track, and the PR3 connected to your computer, nothing else. There's not enough power to run a throttle.
Come to think of it, you probably don't need termination enabled on the PR3 for this, because you will be sending commands via the track connection, not Loconet. If you have the board addressed you actually might be able to operate it connected to track power via your PowerCab and interface. Board setup requires a Digitrax throttle or connection via JMRI - but that sort of connection requires a command station.
If the club DCS is only used to power the signals - you cn get just the grey plugs on the front, and for signal testing you can power it with the fixed AC output on an old power pack - so you could cart it all home but leave the wiring in place at the club.
You don't have the SE8C connected to track power do you? You should power it from its own PS14 or other power supply, not from the track.
The SEC is fine trackside with the DS100
I'm running the SE8 on a 16.5 volt, 40VA transformer with 5 amp rated bridge rectumfinder.
Trackside it doesn't respond to any commands unless the DS100 track power is energized even though it isn't powered from the track. I want to command it from the PC using a PR3 and it's same 40va power source. It will take configuration but wont recognize switch commands from the PC via PR3 with no DS100.
That's OpSw 14, you have to close it for the SE8C to take commands from the Loconet. By default it reads the accessory turnout commands fromt he track feed, which is why track power needs to be turned on.
To use it standalone with a PR3 - it MIGHT work, you need to close OpSw 14, and put the PR3 in "MS100 mode" (I kinda wish they hadn;t called it that - it doesn;t really act like an MS100, it's buffered like a Locobuffer) and also enable Loconet termination on the PR3 - also not a great term, as it isn't 'terminating' anything like the terminating resistors from thinet ethernet days, it's actually PROVIDING a current source for the Loconet. That will allow Loconet traffic without a DSC100 or other command station.