Aspect Controller for Common Anode Signals ASP2

BLOCKsignalling ASP2 Infra red Train Detector (IRTD)

The Signal Controller detects trains by bouncing invisible Infra-Red (IR) light off the underside of the rolling stock, and detecting the light reflected back. Once triggered by the train, the module runs built-programs to simulate the operation of 2-, 3- or 4-aspect signals.

All signals normally show green. When the train passes the detector, the signal switches to red. Once the train has fully cleared the detector, the module switches the signal back to green (via yellow and double yellow if appropriate).

The duration of the red, yellow and double yellow stages can be adjusted as can the time the sensor needs to be cleared before initiating the sequence returning to green and the sensitivity of the detection. Adjusting the time the sensor needs to be cleared can be useful to prevent incorrect detection of the train having passed due to the small gaps between the rolling stock.

This item is available in this ground switching version (where each of the channels switches to ground, and there is a common +5V output) and +12V switching version (where there is a common ground terminal, and each output switches to 12V). The remainder of this document is for the ground switching version.


Features

No calibration required – works out of the box.
No modifications required to rolling stock.
Not affected by light or dark, or changes in light level.
Can be powered from AC or DC supplies.
Designed and manufactured in the UK using lead-free solder and renewable energy.

 

Power Supply

The module operates from any DC power supply between 8V and 25V DC, or any AC power supply between 8V and 16V AC.

Where a choice is a available, a 12V DC supply is recommended.

Please double check all wiring before applying power, as incorrect wiring can damage the unit.

 

Programming

Programming for the particular application can be completed before or after testing the wiring, and also before or after completing the installation.
This is performed by inserting a link between the A and K terminals and holding down the Push Button when switching on the power (it will also work if the Infra-Red sensor has been connected to the A and K terminals).


For each program there are two values to be stored.
The red led on the PCB flashes at 1 second intervals. When the required number of flashes is seen (see later for the list of possible choices) the button is released to store the first value. At this point the led comes on for five seconds to confirm the value is stored.
The led then starts flashing again, and this time the button needs to be pressed to store the second value.
Once both values have been are entered, the led flashes 10 times rapidly, and the module starts operating.
Each value entered can be up to 255 flashes. If more are seen, or the programming is aborted by switching off, then the programming must be repeated.

PCB LED

The led on the PCB has four modes of operation:

1. full brightness (during programming)
2. 10% brighness, filckering (whilst searching for a train)
3. 50% brighness, flashing (whilst waiting for a train to clear the sensor)
4. off (module is no longer searching for a train)

Factory Reset

To reset the module back to factory settings, switch off the power to the module and hold down the Push Button. Apply the power and continue holding the push button until 1 flash of the led is seen. At this point, release the button. You will see a long flash of five seconds.
The led will begin flashing again. When you have seen 1 flash press the button. You will see a long flash of five seconds and then 10 rapid flashes. The reset procedure is then complete and the module will restart with factory settings, and run the lamp test mode. If you make a mistake programming, simply repeat the process.

The default settings are:

Red Time: 1sec
Amber Time: 1sec
Double Amber Time: 1sec
Release Time: 2sec
Sensitivity: 5 (range 1 to 10, with 1 being the most sensitive and 10 being the least sensitive)

 

Led Connection

When using leds it is important to connect them the right way around.

The negative lead (cathode) is identified by a flat on the side of the led body, and by having a shorter lead.
wiring up leds

 

Testing Wiring

As supplied, the module is programmed to run a lamp test sequence. First all outputs are switched on, then they all go off except ch1. Then ch1 is switched off and ch2 comes on. This sequence continues until ch6 is on and then all the outputs are switched off and the sequence is repeated. Each step takes 1 second. The led on the PCB switches on and off with each step (providing A and K are linked, or the IR sensor is connected).



This test sequence is ideal for testing system output wiring before programming for the actual requirement.


Testing the Infra-red Detection

An Infra-Red source and Infra-Red detector are moulded into a single 5mm x 6.5mm package that can be located below the track bed to reflect light off rolling stock.
RPR220 connections

 

Identify the leads from the diagram below and connect to the terminals marked A, K, C and E on the PCB. The wires can be extended using small chocolate block and extra lengths of cable if required (not supplied).

 

Sensitivity Setting

The module is supplied with the sensitivity pre-set to suit most installations and should not need adjustment.

In locations such as tunnels, or when the module is not being used under the track bed, then it may be desirable to adjust the detection threshold.

The sensitivity is factory set to 5, and can be adjusted from 1 to 10 (with 1 being the most sensitive and 10 being the least sensitive).

 

To change the sensitivity, switch off the power to the module and hold down the Push Button. Apply the power and continue holding the Push Button until 9 flashes of the led are seen. At this point, release the button. You will see a long flash of five seconds.

The led will begin flashing again. When you have reached the desired number of flashes to set the new sensitivity, press the button. You will see a long flash of five seconds and then 10 rapid flashes. The programming is then complete and the module will restart. If you make a mistake programming, simply repeat the process.

Performing a factory reset will reset the sensitivity setting back to 5.

 

Installation

The Infra-Red sensor is normally installed below the track-bed.
The detection range of the unit is up to approximately 25mm from the face of the package when normal sensitivity is set using the adjuster on the PCB (for dark surfaces with low levels of reflectivity).

 

The detector can be mounted in an 8mm hole drilled through the track baseboard. If required, the detector can be held in place using a small amount of blutack, expanded polystyrene or similar.
The led diameter is 2.2mm, so on smaller scales the leds can still have a clear view between the sleepers.



Connecting the Outputs

Each channel output has a transistor, which conducts to ground to switch the output to on. This means that any devices such as leds connected to an output will be switched to ground to operate them.
It is recommended that leds are fed from the +5V DC output terminal provided for this purpose and have a 300 ohm current limiting resistor in series.
In cases where the leds are never on together, such as with the two-aspect signal, they can share the same resistor.

Where multiple leds may be on together (for instance with four aspect signals, where the two yellows will be on together) those leds should have their own separate resistors. If in doubt, you can use a separate resistor for each led.

 

Program 1 – Lamp Test Mode

This is a test program to switch the output channels in a set sequence and is the default mode when the unit is supplied.


In this sequence, first all outputs are on, then they all go off except ch1. Then ch1 is switched off and ch2 comes on. This sequence continues until ch6 is on and then all the outputs are switched off and the sequence is repeated. Each step takes 1 second. The led on the PCB switches on and off with each step (providing A and K are linked, or the IR sensor is connected).
To select this program, switch off the power to the module and hold down the Push Button. Apply the power and continue holding the push button until 1 flash is seen. At this point, release the button. You will see a long flash of two seconds and then the led will begin flashing again.
When 1 flash has been seen press and hold the button. You will see a long flash of five seconds and then 10 rapid flashes. The button can now be released and the programming is complete. The module will start running the program. If you make a mistake programming, simply repeat the process.

 


Program 2 - 2-Aspect Signalling



This program simulates the operation of a two aspect signal, which is normally showing green. The module searches for a train, and if one is detected in front of the sensor, the signal immediately switches to red.

Whilst the sensor is covered, the signal stays at red. As the train passes over the sensor, any gaps between the rolling stock which are shorter that the release time programmed are ignored.

Once the train has cleared the sensor, and the release time expires, then the "red time" timer starts. When this expires, the signal turns back to green and starts looking for trains again.

The "release time" can be adjusted if slow moving trains cause the signal to prematurely switch back to green before the train has cleared the sensor.

The "red time" can be adjusted to a realistic duration for a train to clear the section of track protected by the signal.

Channels 3 and 4 can be used to operate remote led indications to mimic the operation of the main signal, for use on a control panel or mimic.

 

When supplied, or following a factory reset, the module will operate in lamp test mode. It needs to be reprogrammed as follows.

To select this program, switch off the power to the module and hold down the Push Button. Apply the power and continue holding the push button until 2 flashes are seen. At this point, release the button. You will see a long flash of two seconds and then the led will begin flashing again.

When 2 flashes have been seen press and hold the button. You will see a long flash of five seconds and then 10 rapid flashes. The button can now be released and the programming is complete. The module will start running the program. If you make a mistake programming, simply repeat the process.

 

Program 3 3-Aspect Signalling



This program simulates the operation of a three aspect signal, which is normally showing green. The module searches for a train, and if one is detected in front of the sensor, the signal immediately switches to red.

Whilst the sensor is covered, the signal stays at red. As the train passes over the sensor, any gaps between the rolling stock which are shorter that the release time programmed are ignored.

Once the train has cleared the sensor, and the release time expires, then the "red time" timer starts. When this expires, the signal switches to amber and the "amber timer" starts.

When this expires, the signal switches back to green and starts looking for trains again.

Channels 4,5 and 6 can be used to operate remote led indications to mimic the operation of the main signal, for use on a control panel or mimic.

 

The "release time" can be adjusted if slow moving trains cause the signal to prematurely switch back to green before the train has cleared the sensor.

The "red time" can be adjusted to a realistic duration for a train to clear the section of track protected by the signal.

The "amber time" can be adjusted to a realistic duration for the scale.

 

When supplied, or following a factory reset, the module will operate in lamp test mode. It needs to be reprogrammed as follows.

To select this program, switch off the power to the module and hold down the Push Button. Apply the power and continue holding the push button until 2 flashes are seen. At this point, release the button. You will see a long flash of two seconds and then the led will begin flashing again.

When 3 flashes have been seen press and hold the button. You will see a long flash of five seconds and then 10 rapid flashes. The button can now be released and the programming is complete. The module will start running the program. If you make a mistake programming, simply repeat the process.

 

Program 4 4-Aspect Signalling



This program simulates the operation of a four aspect signal, which is normally showing green. The module searches for a train, and if one is detected in front of the sensor, the signal immediately switches to red.

Whilst the sensor is covered, the signal stays at red. As the train passes over the sensor, any gaps between the rolling stock which are shorter that the release time programmed are ignored.

Once the train has cleared the sensor, and the release time expires, then the "red time" timer starts. When this expires, the signal switches to amber and the "amber timer" starts.

When this expires, the signal switches to double amber and the "double amber timer" starts. When this expires, the signal switches back to green and starts looking for trains again.

Channels 5 and 6 can be used to operate remote led indications to mimic the operation of the main signal, for use on a control panel or mimic. In this case, the green led operates only when the signal displays green, otherwise the red led on the panel is lit for all other signal combinations.

 

The "release time" can be adjusted if slow moving trains cause the signal to prematurely switch back to green before the train has cleared the sensor.

The "red time" can be adjusted to a realistic duration for a train to clear the section of track protected by the signal.

The "amber time" and "double amber" can be adjusted to a realistic duration for the scale.

 

When supplied, or following a factory reset, the module will operate in lamp test mode. It needs to be reprogrammed as follows.

To select this program, switch off the power to the module and hold down the Push Button. Apply the power and continue holding the push button until 2 flashes are seen. At this point, release the button. You will see a long flash of two seconds and then the led will begin flashing again.

When 4 flashes have been seen press and hold the button. You will see a long flash of five seconds and then 10 rapid flashes. The button can now be released and the programming is complete. The module will start running the program. If you make a mistake programming, simply repeat the process.

An alternative wiring method using fewer resistors is shown below:

 

Changing the Timing of each Phase

The individual time for each of the phases can be adjusted to suit (as supplied they are set to 1 second each, which is ideal for initial testing).  Once you are happy with the operation of the train detection, you will probably want to change these to more realistic values.

To change the Red Time:

Switch off the power for 5 seconds.  Press the push button on the PCB, and switch the power back on.

The red led on the PCB flashes at 1 second intervals. When 3 flashes have been seen, the button is released to store the first value. At this point the led comes on for five seconds to confirm the value is stored.
The led then starts flashing again, and this time the button needs to be pressed to store the second value (the time you want the red led to be lit, for example 10 flashes for 10 seconds).
When the button is released, the led flashes 10 times rapidly, and the module starts operating.

To change the Yellow Time:

Switch off the power for 5 seconds.  Press the push button on the PCB, and switch the power back on.

The red led on the PCB flashes at 1 second intervals. When 4 flashes have been seen, the button is released to store the first value. At this point the led comes on for five seconds to confirm the value is stored.
The led then starts flashing again, and this time the button needs to be pressed to store the second value (the time you want the yellow led to be lit, for example 10 flashes for 10 seconds).
When the button is released, the led flashes 10 times rapidly, and the module starts operating.

To change the Double-Yellow Time:

Switch off the power for 5 seconds.  Press the push button on the PCB, and switch the power back on.

The red led on the PCB flashes at 1 second intervals. When 5 flashes have been seen, the button is released to store the first value. At this point the led comes on for five seconds to confirm the value is stored.
The led then starts flashing again, and this time the button needs to be pressed to store the second value (the time you want both yellow leds to be lit, for example 10 flashes for 10 seconds).
When the button is released, the led flashes 10 times rapidly, and the module starts operating.

 

 

Programming Options

The following diagram shows all the programming options.

 

Any signals show in diagrams and photos are only to illustrate connections and are not included with the module.

 

Troubleshooting

Q. The red led on the PCB does not work.

A1. Check the supply polarity.  The positive (+) supply should be to the ACIN/+ terminal and the negative (-) supply should be to the GND terminal.  Do not exceed 12V DC in otherwise the module and the attached signals may be damaged.

A2. Check the sensor is connected correctly and that its wires are correctly seated in the terminals.

A3. Briefly short terminal A to terminal K.  This should result in the red PCB led operating.  If this test works, but the red PCB led is not seen when the IR sensor is connected then this points to incorrect wiring to the sensor, or a defective sensor.

 

Q. The attached signal does not light up.

A1. This module works with common anode signals.  These have the positive wires from the signal's leds connected together.  If your signals have common cathodes they will not work with this module.

A2. Signals need a series resistor to limit the current and prevent them from being damaged from operating too brightly.  If they are operated without this they may be damaged.

 

Q. When the module is powered up a signal other than green is shown.

A1. The module needs to be programmed to match the number of aspects that the signal has.  If this is not correct, then an incorrect colour could be show when powering the module.

A2. As supplied, and following a factory reset, the module shows a test sequence.  It needs to be programmed to match the number of aspects that the signal has before use.

A3. The module is being triggered, even when there is not train.  Remove the sensor from the board and hold it away from surfaces in front of the sensor.  Check if is now starts on a green aspect.