Wiring Atlas O signals

I acquired some Atlas 3 position signals. I want to know is there a way to wire them so that if I set one at one of a long block, and the other at the end of that block, reguardless of which end a train enters the block, it will turn both signals red. I do not want to used isolated rails, as signals would be placed in front a double crossover at both ends of the block.

Thanks,

Ed

Original Post

Ed, I installed Atlas O Signals on my layout.  I used a couple isolated rails on short single track sections through switch areas.  Both signals will need to be hooked to the combined hop-scotched single track sections.

When one of the tracks is bridged, the signals will turn red.  The automatic timing in the signal will then turn yellow to green on both signals, once the engine or cars are out of the area.  Movement along the pathway of any single track isolated rails keeps the signal red, until the track section(s) are vacated.  Each signal should have its own board wired to the pattern of isolated rails.  (Two or three single isolated rail tracks will trigger the signal to red. You don't need a long stretch of track because the length of the train will continue bridging the connection for the signals.)   A slow moving single engine might have difficulty making it from one isolated rail to the next.  A train should not have this difficulty.

The hop-scotch pattern of isolated rails allows you to power both outside rails on non isolated track sections.  This will help Legacy Remote Signals reach your engines better, especially with Atlas O track.

The downside of this is that the remote daisy chaining of signals will not work with this section of track.  The daisy chain is good on a circle of track in one direction to speed up the changing of the red to yellow to green.  (This is for large layouts.)

Sincerely,  John Rowlen

Ed, I you do not want isolated rails, Lionel makes a motion detecting accessory. One at each end will trigger the signals.  The down side is that a slow moving train may not get out of the block before the accessory turns the blocks loose to go yellow to green.

Eric Segal did a video on Atlas O signals.  Youi may want to watch it.

Sincerely, John Rowlen,

John Rowlen posted:

Ed, I you do not want isolated rails, Lionel makes a motion detecting accessory. One at each end will trigger the signals.  The down side is that a slow moving train may not get out of the block before the accessory turns the blocks loose to go yellow to green.

Eric Segal did a video on Atlas O signals.  Youi may want to watch it.

Sincerely, John Rowlen,

John,

I would like to use something like the Lionel or MTH iPad. I tried using a DZ-1070 and 1075, but neither would even trigger the Atlas signal. Again my goal is to have the signals at each end of the block to change colors in unison. I did this with the DZ-1075 and DZ-1070 and a MTH signal bridge. But the electronics of the Atlas signals seem to not allow this type of setup.

Ed

 

Not clear what you have.  From the Atlas website, it appears their signal heads come with a modular phone plug that snaps into a circuit board hidden in a shed.  And the circuit board is looking for an insulated-rail trigger.  Is this what you have?  Model numbers if you know them would help.

Untitled

If this is what you have, then you can use two Lionel 153IR occupancy detectors (or two MTH ITADs), to provide the equivalent of an insulated-rail-trigger.  That is, the relay inside the 153IR could be configured to apply the outer-rail voltage via its "NO" terminal when triggered.  The two "NO" terminals could be tied together going into the signal electronics so either (or both) would activate the signal.

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stan2004 posted:

Not clear what you have.  From the Atlas website, it appears their signal heads come with a modular phone plug that snaps into a circuit board hidden in a shed.  And the circuit board is looking for an insulated-rail trigger.  Is this what you have?  Model numbers if you know them would help.

Untitled

If this is what you have, then you can use two Lionel 153IR occupancy detectors (or two MTH ITADs), to provide the equivalent of an insulated-rail-trigger.  That is, the relay inside the 153IR could be configured to apply the outer-rail voltage via its "NO" terminal when triggered.  The two "NO" terminals could be tied together going into the signal electronics so either (or both) would activate the signal.

Yes this is what I have. Tried tieing two signals together, the normally open (NO), to the DIN connection on  both siginals. One worked fine, the other stayed at a constant yellow.

 

 

If you drive JUST the "constant yellow" signal with the NO-to-DIN wiring, does it work?  In other words is it the simultaneous connection of the NO to both DIN causing the problem?

And to be clear, the constant yellow means all the time (it is never green or red)?

Now I'm confused as to what you have.  You responded to a comment about hooking NO to "Rin".  I don't see "Rin" on the diagram I copied from Atlas.  

And exactly where is your "NO" signal coming from?  Do you have a 153IR or MTH ITAD hooked up?

Using the diagram I copied (with DIN), you should be able to power both signals leaving both DINs disconnected.  The signals should both be GREEN.  You should be able to take a piece of wire and momentarily touch an outer-rail to the DIN and both signals should turn to RED.   If you don't get this behavior, then using a 153IR or MTH ITAD will not change anything.

I again recommend you follow Atlas O instructions and create a series of short isolated rails through this section of track.  Hook the isolated rail to "din" on the board for each signal.

If using Atlas O track, it allows you to power both outside rails on sections between the isolated rail tracks.

I am using Legacy that is helped by a clear signal through the rails.

Sincerely, John Rowlen

Untitled

Assuming you have an MTH Scaletrax ITAD as shown above.  Using the terminology of the Atlas diagram shown earlier, the "PWR" and "COM" connections from the train transformer must be as shown above; this may seem swapped/backwards but this is how to emulate the insulated-rail trigger method using an ITAD.

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stan2004 posted:

Untitled

Assuming you have an MTH Scaletrax ITAD as shown above.  Using the terminology of the Atlas diagram shown earlier, the "PWR" and "COM" connections from the train transformer must be as shown above; this may seem swapped/backwards but this is how to emulate the insulated-rail trigger method using an ITAD.

This method works fine when connecting to just one signal (NO to din #1 on switch 1). But if you connect switch 2 (din #2) to the same iPad, both signals turn red and never change. 

So simply connecting DIN #1 to DIN #2 is triggering both signals to turn RED.  

In which case this has nothing to do with using an ITAD or insulated-rail triggering.  It's a question of how to simultaneously trigger two (or more) Atlas signals "in parallel" so to speak.  More info is needed on how the DIN input works; it stands to reason this configuration was considered when the Atlas signal system was designed.

If no one comes forward with the "secret" to DIN operation, one brute-force option would be to have the ITAD(s) trigger a double-pole relay (about $10 for a DPDT relay module).  The double-poles would isolate the two DIN input when the signals are meant to be yellow/green...but then connect both DINs to the outer-rail when triggered.  Or, if in your quest, you come across the schematic of the board that sits in the shed perhaps the circuitry around the DIN input would suggest an even simpler method.

John Rowlen posted:

I again recommend you follow Atlas O instructions and create a series of short isolated rails through this section of track.  Hook the isolated rail to "din" on the board for each signal.

If using Atlas O track, it allows you to power both outside rails on sections between the isolated rail tracks.

I am using Legacy that is helped by a clear signal through the rails.

Sincerely, John Rowlen

John,

My original post stated that I wanted to have two Atlas signals both turn red at the same time, regardless of which end of the block you entered from. So this is just one block with a signal at each end. The way that Atlas engineered these signals does not allow for this reguardless if itads or connecting to the insulated rail. Since there is only one block the two din connections are basically tied together, and the signals both go to red and will stay that way. The isolation of the rail does not come into play since both din connections go to the shared rail.

Ed

Let me understand this.  If you connect the MTH ITAD 'NO' terminal to the Atlas signal DIN#1 the signal works like you want (Turns red, but after a while goes yellow then green.), correct?  If so place one ITAD and signal at each end of the stretch you want the signals to be and wire them up like that.  Now to tie them together so they trigger at the same time run one wire from the 'NO' terminal of the ITAD at one end to the 'NO' terminal of the ITAD at the other end.  In this way you are basically giving each signal the same dual trigger.

Do not run any wires between the Atlas signals.  You only run wires between the Atlas signals if you want one to control the other for sequential signaling, which is not what you want.

sinclair posted:

Let me understand this.  If you connect the MTH ITAD 'NO' terminal to the Atlas signal DIN#1 the signal works like you want (Turns red, but after a while goes yellow then green.), correct?  If so place one ITAD and signal at each end of the stretch you want the signals to be and wire them up like that.  Now to tie them together so they trigger at the same time run one wire from the 'NO' terminal of the ITAD at one end to the 'NO' terminal of the ITAD at the other end.  In this way you are basically giving each signal the same dual trigger.

Do not run any wires between the Atlas signals.  You only run wires between the Atlas signals if you want one to control the other for sequential signaling, which is not what you want.

 

ehkempf posted:
sinclair posted:

Let me understand this.  If you connect the MTH ITAD 'NO' terminal to the Atlas signal DIN#1 the signal works like you want (Turns red, but after a while goes yellow then green.), correct?  If so place one ITAD and signal at each end of the stretch you want the signals to be and wire them up like that.  Now to tie them together so they trigger at the same time run one wire from the 'NO' terminal of the ITAD at one end to the 'NO' terminal of the ITAD at the other end.  In this way you are basically giving each signal the same dual trigger.

Do not run any wires between the Atlas signals.  You only run wires between the Atlas signals if you want one to control the other for sequential signaling, which is not what you want.

 

If you connect like you suggest, with out tying the two ITAD's together via the NO connection each signal will operate correctly, but will be totally independent. If you now connect the two ITAD's together via the NO connection you are also connecting the two Atlas DIN connections together since they connect to the NO connection. Once the two DIN connections are tied together both signals turn red and stay that way and do "NOT" turn back to yellow or green.  

Ed,

I followed the Atlas O instructions and have four target blocks triggered by the same isolated rails across my Atlas O Single Pratt bridge.  When the engine gets onto a point five inches into the bridge (I cut the isolated rail with a right angle Dremel saw)  the isolated rail trips four target signals to red.  When the sections of track are vacated, the automatic feature of the Target signals four control boards turns the four individually yellow, then green again.  I have four wired to the same isolated rail sections. One on each side of my double crossover.  The targets work from either direction.

In the last pictures you can see that I put a communication cable between/starting at the target and running to a G-Signal, so when the Target turns red, the G Signal turns Yellow.  The G-Signal is independent the other way, as it approaches the Interlock at the bridge and runs on the automatic timing.  It works. Call me lucky.

The isolated rails also trip targets on each of the parallel tracks crossing the interlock the other way.  Isolated rails, with each control board connected to them, running in automatic mode. (No plug-in connecting cables)

Good luck.

Sincerely, John Rowlen

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Ed, 

Here are two pictures of the G-Signal running on automatic as the train approaches the interlock.  As the Big Boy approaches and hits the isolated rail, the G-Signal changes to Red.  Once the train is off the isolated rail section, the automatic feature causes the G-Signal to turn yellow then green.

The isolated rail starts just ahead of where the Big Boy Cab passes the G-Signal.  The section of isolated rail is only 30" approximately, until the isolated rail for the Target Signals for the Bridge Right-of-way start. 

There are two isolated rail sections for the Bridge Traffic on either side of the interlock 90-degree cross-over.  They are about 30" and 28" on each side of the cross over.

The track to the left is also wired this way for its G-Signal that is connected from that track's Target Signal to the G-Signal on its track.

Sincerely, John Rowlen

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ehkempf posted:
ehkempf posted:
sinclair posted:

Let me understand this.  If you connect the MTH ITAD 'NO' terminal to the Atlas signal DIN#1 the signal works like you want (Turns red, but after a while goes yellow then green.), correct?  If so place one ITAD and signal at each end of the stretch you want the signals to be and wire them up like that.  Now to tie them together so they trigger at the same time run one wire from the 'NO' terminal of the ITAD at one end to the 'NO' terminal of the ITAD at the other end.  In this way you are basically giving each signal the same dual trigger.

Do not run any wires between the Atlas signals.  You only run wires between the Atlas signals if you want one to control the other for sequential signaling, which is not what you want.

 

If you connect like you suggest, with out tying the two ITAD's together via the NO connection each signal will operate correctly, but will be totally independent. If you now connect the two ITAD's together via the NO connection you are also connecting the two Atlas DIN connections together since they connect to the NO connection. Once the two DIN connections are tied together both signals turn red and stay that way and do "NOT" turn back to yellow or green.  

Then something is not set up correctly, or is wrong with the control boards.  I can not think of any reason for that behavior of your signals.

Ed,

I recommend getting one signal to work properly through your isolated rail section.

Install the other at the other end later, then wire it to the isolated rails.

There should only be the two power wires to the computer board, plus the wire to the isolated rail, and the signal plug installed into the computer board.

The two power wires supply power for lighting the signal.  The isolated rail tells the computer board to change the lights on the signal.  The Signal Plug pulls power from the board and receives communications.  The board has the automatic timing for changing the light sequence programmed into it.

No other wires should be connected to the board.  Check that the power wires are going to the correct poles.  The isolated rail is only one wire and needs the input of the power wires.  I wish you luck.  If one signal works, try the next.  I did have one control board that did not work correctly.  Try a different board on a signal that isn't working.

I just remember that the power wires can be daisy chained with a set of set screw clips for power input and a set for power output. It does not make sense that there would be a difference between the sets, but try switching the power wires to the other pair of input/outputs.

Check your signals by plugging them into a board you get to work.  Then you will know your signals are good.

Swap the boards onto the signal that you get to work to verify that each computer board is good. 

Good luck and best wishes.  Have a good weekend.

Sincerely, John Rowlen

sinclair posted:
ehkempf posted:
ehkempf posted:
sinclair posted:

Let me understand this.  If you connect the MTH ITAD 'NO' terminal to the Atlas signal DIN#1 the signal works like you want (Turns red, but after a while goes yellow then green.), correct?  If so place one ITAD and signal at each end of the stretch you want the signals to be and wire them up like that.  Now to tie them together so they trigger at the same time run one wire from the 'NO' terminal of the ITAD at one end to the 'NO' terminal of the ITAD at the other end.  In this way you are basically giving each signal the same dual trigger.

Do not run any wires between the Atlas signals.  You only run wires between the Atlas signals if you want one to control the other for sequential signaling, which is not what you want.

 

If you connect like you suggest, with out tying the two ITAD's together via the NO connection each signal will operate correctly, but will be totally independent. If you now connect the two ITAD's together via the NO connection you are also connecting the two Atlas DIN connections together since they connect to the NO connection. Once the two DIN connections are tied together both signals turn red and stay that way and do "NOT" turn back to yellow or green.  

Then something is not set up correctly, or is wrong with the control boards.  I can not think of any reason for that behavior of your signals.

I have two atlas signals. Both work perfectly if each is connected to it’s own iTad, or two separate isolated blocks. I therefore would normally assume that there is no problem with either signal. Now let’s take the itads and isolated blocks out of the equation. With only power going to each signal control board, and the signal plugged into its rj45 connection, and only one wire coming out of the din connection of each signal control board, try the following. Touch the ends of the two din connected wires together. In my case both signals go from green to red and stay that way. So based on that exercise, connecting them to the same block would only have the same result since the rail is nothing more that a extended connection to the two din wires.

It very well could be a bad board as I stated above.  It does happen.  Put a piece of tape on the boards that don't work.  Check the picture of my under-table installation.  Make sure your signal cable is going into the correct plug socket (middle of the board).  See the picture of several of my boards at the interlock.

Look at the four boards on the right side of photo.  The board at the very top does not have a signal plugged into it yet.

There are also three photos of the Target Signal for the Bridge traffic.  More were added later for the opposite direction.

Sincerely, John Rowlen

DSCN0926

 

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Connecting the two din is NOT the same as connecting each to the same isolated rail unless there is a problem with your boards. There should be no power coming out or to the din.  Only when the train is on the isolated rail should the bridge power to the din, triggering the signal to red. 

One of your boards has a hot din connector.  NOTHING should happen by connecting the two din together of the two computer boards without the train bridging the gap and providing power through the isolated rail.

Where is the power coming from?  I do not have that issue. It has to be that one or both boards are bad.  I would swap in another board.  The din is getting power from somewhere or the signal would not turn red.  Check that the ground and hot are to the same inputs on each board. 

I had to carefully color-code all wires to avoid wiring issues. Yellow and blue were power. Green was the isolated rail.

Sincerely, John Rowlen

First off I want to thank all that took the time to reply. I am a idiot. Like I said both signals worked fine when not tied together, so I didn’t think anything was wrong with either signal. I went back to check the power wiring and sure enough I had reversed hot and common on one of the boards. That did not prevent it from working independently, but when tied together with the other signal all went south. Wired it correctly and all works as at should. Again I thank all of you for your input and patience with me.

Thanks,

Ed

 

 

stan2004 posted:

Untitled

Assuming you have an MTH Scaletrax ITAD as shown above.  Using the terminology of the Atlas diagram shown earlier, the "PWR" and "COM" connections from the train transformer must be as shown above; this may seem swapped/backwards but this is how to emulate the insulated-rail trigger method using an ITAD.

You would need to jumper the outer rail(COM) terminal to the ITAD COM screw (remove any installed jumper first) to route the common (which is really ground that the Atlas board is looking for to operate).

 

Thanks,

Sam

Free lancing fictitious Iowa Midwest Division of Pittsburgh & West Virginia Railway

Take a cab and trolley ride on P&WV  https://www.youtube.com/watch?...7pZJZBL_4&t=144s

 

BE WITH THOSE THAT BRING OUT THE BEST IN YOU,

          NOT THE STRESS IN YOU.

          unknown

stan2004 posted:

  More info is needed on how the DIN input works; it stands to reason this configuration was considered when the Atlas signal system was designed.

If no one comes forward with the "secret" to DIN operation,

Hi Stan,

I traced out all the various boards on my Custom Signal/Atlas signal installation (schematics available upon request, no guarantee they are perfectly correct ).  Basically DIN (and most other inputs) are pulled high by a 47K resistor to +5V.  This high runs through a series 470K resistor into the PIC 16xxx processor.

 

Thanks,

Sam

Free lancing fictitious Iowa Midwest Division of Pittsburgh & West Virginia Railway

Take a cab and trolley ride on P&WV  https://www.youtube.com/watch?...7pZJZBL_4&t=144s

 

BE WITH THOSE THAT BRING OUT THE BEST IN YOU,

          NOT THE STRESS IN YOU.

          unknown

rrman posted:
stan2004 posted:

Untitled

Assuming you have an MTH Scaletrax ITAD as shown above.  Using the terminology of the Atlas diagram shown earlier, the "PWR" and "COM" connections from the train transformer must be as shown above; this may seem swapped/backwards but this is how to emulate the insulated-rail trigger method using an ITAD.

You would need to jumper the outer rail(COM) terminal to the ITAD COM screw (remove any installed jumper first) to route the common (which is really ground that the Atlas board is looking for to operate).

Hi Sam,

Not sure I understand what you're saying.  The ITAD has an internal connection which shorts (shown in ORANGE) the center "COM" screw-terminal to the adjacent screw-terminal as shown in following.

untitled

The ITAD's NO and NC outputs come from the far right ITAD terminal shown in BLUE in above photo.   In other words the center "COM" screw terminal does NOT go to the common terminal of the internal SPDT relay.  This is certainly not obvious and has been the source of much confusion, consternation, etc.  The Lionel 153IR occupancy detector uses a similar scheme.

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rrman posted:

...I traced out all the various boards on my Custom Signal/Atlas signal installation (schematics available upon request, no guarantee they are perfectly correct ).  Basically DIN (and most other inputs) are pulled high by a 47K resistor to +5V.  This high runs through a series 470K resistor into the PIC 16xxx processor.

Why not just post the schematics here?  

But you've explained why the OP was triggering BOTH signals by merely connecting the DIN inputs if the AC power inputs are swapped.  The 47K to +5V provides enough current thru the 470K given the local DC power supply to each board surely uses non-isolated (just diodes) rectification. 

stan2004 posted:
rrman posted:

...I traced out all the various boards on my Custom Signal/Atlas signal installation (schematics available upon request, no guarantee they are perfectly correct ).  Basically DIN (and most other inputs) are pulled high by a 47K resistor to +5V.  This high runs through a series 470K resistor into the PIC 16xxx processor.

Why not just post the schematics here?  

But you've explained why the OP was triggering BOTH signals by merely connecting the DIN inputs if the AC power inputs are swapped.  The 47K to +5V provides enough current thru the 470K given the local DC power supply to each board surely uses non-isolated (just diodes) rectification. 

Here ya go.  Other Custom Signal boards pretty much followed this design.

Custom Signals CPL SBC 1

 

 

 

 

Thanks,

Sam

Free lancing fictitious Iowa Midwest Division of Pittsburgh & West Virginia Railway

Take a cab and trolley ride on P&WV  https://www.youtube.com/watch?...7pZJZBL_4&t=144s

 

BE WITH THOSE THAT BRING OUT THE BEST IN YOU,

          NOT THE STRESS IN YOU.

          unknown

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ehkempf posted:

First off I want to thank all that took the time to reply. I am a idiot. Like I said both signals worked fine when not tied together, so I didn’t think anything was wrong with either signal. I went back to check the power wiring and sure enough I had reversed hot and common on one of the boards. That did not prevent it from working independently, but when tied together with the other signal all went south. Wired it correctly and all works as at should. Again I thank all of you for your input and patience with me.

Thanks,

Ed

 

 

Glad you got it figured out.  I knew something had to be up as Atlas gives instructions for bi-directional signaling which are basically what I said to do.  But seeing you ran into this issue I now have another tidbit to troubleshoot with when I get around to adding Atlas signals to my layout.

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