17 Sep 2009

Block Detection Visible on Computer

Here is the first screen showing a live block occupancy detection on demo version of RR&Co software.

As the loco enters the section the block turns from yellow to red and as it leaves it turns back to yellow again.

Now I just need to try putting three separate detection sections into a single logical block.

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13 Sep 2009

Block Occupancy Detection

A key part of the infrastructure on the planned railway is 'block occupancy detection' - a set of circuitry that allows you to know if part of the track is occupied.

For this I am using the BDL 168 from Digitrax. It is suitable for the other loconet devices that I am running For example it tells the DTM30 that a section of track is occupied via loconet avoiding lots of long wires for LED displays, it also interacts with SIGM20 signal controller to automatically control signals, and finally it provides vital information to the computer to allow it to automagically run trains, and hopefully avoid crashes.

It took me sometime to understand the wiring diagrams, they are highly ambiguous - but for my simple test setup you just connect Zone Common wire to the main Rail A feed. then for the section to be detected remove the Rail A wire from wherever it was previously connected and join to any of the 16 detection section pins on the DBL connector. And that is it.

Learning points - I will need to plan lots of rail gaps and feeds into the layout before construction to allow sectioning.

Here is the board and connector mounted on a scrap piece of hardboard :-

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And here is it working for the first time, the top LED indicates that the class 25 at the back of the shot is 'in section'.

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And finally here is the full array of electronics I am currently using -

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From the left we have a Team Digital SMD 82 static controller that is operating the one point motor, then the Digitrax controller and PSU and then comes the box containing the CML DTM 30 and finally the DBDL168. I still have to add a SIGM20 and replace the SMD82 with a CML DAC 10.

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8 Sep 2009

Signalling Panel

I have been extravagent and bought three new boards from CML electronics. The first to be implemented is a DTM30 board,
which allows traditional style control of points and (reporting of signal and occupancy states) but using very modern techniques.

In a "traditional" panel you push a switch and it activates a point motor, this is OK, but it has several drawbacks -

Firstly, it means you have lots of wires flowing from the panel to the various motors.

Secondly, it means if, like me, you want to be able to control routes both by computer and from the panel then that is not possible without conflict.

Using this CML board, then there are no direct wires to the point motors instead the board outputs and inputs packets to the Digitrax loconet bus. These instruct the point motors to change state this is then "seen" by the computer and so it is aware, it is also seen by the
static decoder on the point which actually activates the point. Similarly if the computer or "throttle" gives a command to change state of a point that will be picked up on the bus by the DTM30 which can track the change and change the indicator light.

This all means that you only need three connections from the board to the outside world - two loconet connections and a power supply.

I used a maplin £4.99 ABS box, combined with some Hexaganol plastic spacers (12mm) to mount the board on off the floor of the box and a power supply left over from a BT broken home hub that gives up to 2A at 9V DC. I then connected that to a Chassis mount 2.1mm DC socket (FT96E) so that the whole box could be unplugged.

On the top of the box, I have used some 5mm green HB LEDs (CK39) mounted on 5mm LED Clips (YY40) and a sub miniature push switch (JM01B).

Like everything else this is just for test at the moment so I have not made the box too pretty.

I purely want to test out the concepts for the main layout. As so much wiring is involved I want to be sure what I am doing before I start.

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