The Adirondack Line  

Example of Tower Master Installation

Introduction

With the advent of DCC, the opportunity to reduce the number of wiring connections to control a layout became a possibility.  The control of switches (points to the UK fraternity) was possible from handheld throttles, activating accessory decoders (DS54, AD4, DAC10 etc) driving switches or the use of local inputs to the accessory decoders from pushbuttons on the side of the layout. 

However, when controlling a large yard or hidden staging (sidings), this became bit more complex, as one has to remember the DCC address of the switch when using throttles or one may have to check the actual route set by the activation of the local push button. Positional feedback of the switch is currently possible with the use of LEDs, either in the driving circuit of the switch motor (Tortoise) or from a microswitch on the switch motor ( Peco), with layout wiring.   Also, one may not want to walk down to the physical position of the switch to push the local push button in the fascia.

Enter the Tower Master concept. What if one could, by only connecting track power and Loconet :-

• concentrate all of the pushbuttons and switch positional LEDs onto a single or multiple yard panel(s), displaying the track layout that could be used by the Yard Master or Operators. This would reduce the wiring on the layout; the panel could be sited anywhere (or moved easily); the track layout would be shown making it easy for operators to identify ' what controls - what'.
• only show the route selected through the yard - cascading.
• initialise the switches to a defined state on 'power up'.
• visibly and audibly, alert Yard Master, if external throttle activated a switch in his domain.
• have the ability to show track occupancy with an LED, as detected by a Loconet accessory decoder (BDL16 etc).
• avoid complex CV programming with a ' Learn' capability.

Well, this concept is now reality, with the availability of the UK designed Tower Master - DTM16.

Example Installation

The following describes the yard panel designed to manage the main yard in a UK USA prototype layout, using the capabilities of the DTM16. We decided that track occupancy capability was not required in this case. 

The yard is entered from the main line from three directions, under the control of the Dispatcher setting the appropriate switches, with the verbal permission of the Yard Master. The entry points are at the diamond in the centre of the picture, and also from the left into the grey ballasted arrival / departure tracks

.

The yard has two arrival / departure tracks, four classification tracks, caboose track, two coach tracks and four tracks to the loco facilities.

Control Panel

    Front of panel

  The red lines on the track plan show the three entry points from the main line that are under Dispatcher control.  The remainder of the tracks are under the control of the Yard Master and the Tower Master circuits. Single LED on top right is track power repeater

At the top left, is an entry from the main line leading to the two arrival / departure tracks, with a central crossover for convenient switching. The track continues to the right, through a double slip, where the four classification tracks, diverge below the arrival / departure tracks. One leg of the double slip is another main line entry point.

Continuing to the right, the yard lead diverges down and meets the caboose track coming from the classification yard. Next, we have another mainline entry point, with the track diverging into the upper two coach tracks and the remainder to the loco facilities.

If one pushes a pushbutton, the commands to change the state of the track switch are sent and the LEDs reflect the new position. The board is shown with the cascade function enabled, showing on the lower right, that the route selected is for the lower loco track - note all other LEDs are out above it. Likewise, the route is set for the lower classification track.

The basic DTM16 will drive two LEDs (or one bicolour) for each output cell.  We wanted to extend this capability to be able to take advantage of the ability to detect if an external switch command changed the state of one of the switches which was under yard control, by adding more than two LEDs per cell. So the designer of the DTM16 kindly designed an additional buffer driver circuit to enable more outputs from one cell - Radio Shack components plus two ICs

This is shown on the double slip, where the LED at the end of the mainline track is a bicolour LED. (It is red at this time, but the camera flash washed it out!!).

If the Dispatcher changes the mainline crossover to allow entry to the yard, and audible series of bleeps are heard and the affected LEDs flash and then change to the new state.  In this case, the red LED flashes and changes to green.  The Yard Master can then select if the route is for arrival/ departure tracks, as in this case; or entry to a classification track. Note cascading was not enabled at this stage.

This happens to the entry bicolour LEDs, whenever any of the three entry switches are set for yard entry.

The majority of CVs can be set by a simple 'Learn' capability.  In addition, the DTM16 can have 8 local routes programmed - we choose to not use this feature

    Inside the panel

The pushbuttons and LEDs are connected to the DTM16 on the rear of the panel via ribbon cables.  Normally these would have to lead out to the layout, but in this case they go to the DTM 16.

The small board on the left is the extra buffer board.

Here is the DTM16 installed at the back of the panel. Two ribbon cables for pushbuttons, two for LEDs, Loconet and track power are the only connections.

The two pushbuttons on the right hand side are the initialise and learn buttons external access.

Wow - all those wires within the panel and only Loconet and track power connections.

It looks good and works well.

For further details of the Tower Master DTM16 - please link to CML Electronics

Visitors since 18th March are