Dapol semaphore signals & Train-Tech SC3 decoder

[Chrissaf]

i have three dapol semaphores operating on my railway & i'm intereseted in how they react when railmaster starts up.

As far as I can tell, they change state when the two yellow wires are shorted together. So in simple terms you power the signal up, look at the signal, then press your connected button to set it to the required state. power it down & back up & it remains in that state.

But  when i power up my elink & then start railmaster, the sc3 module appears to put the signal through a short sequence that always ensures that they are set to danger at the end of the startup sequence. This is excellent, as I don't need to worry about resetting them to the correct state, but how does the SC3 manage this? there's nothing in the dapol documentation to suggest a clever startup sequence.

[Chrissaf]

...but how does the SC3 manage this? there's nothing in the Train-Tech or Dapol documentation to suggest a clever startup sequence.

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Look to this screen / Window in your RailMaster configuration. This (yellow highlight) is where you tell the signal (similar option is on the points configuration window as well) what position to start up in. So it has got nothing to do with the SC3 decoder, which is why there is no mention in the Dapol / Train-Tech manuals that cover this.

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[St1ngr4y]

I know nothing about Dapol signals, but I do have a number of TrainTech 2- and 4-aspect signals. In the above image shown by Chris, the words "Startup position" can be interpreted in two different ways. My interpretation is that the number immediately following these words refers to the order that this signal is initialised at startup in relation to all other signals on the layout, so 1 means it will be the first signal to be initialised. The second item on that row, the dropdown box showing "Clear" indicates the command which will be sent to the signal to initialise it i.e. a Clear command to address 15 in the example shown above. This is one of the "flaky" bits of RM's implementation of TrainTech signals, in that for a 3- or 4-aspect signal, you still only have the choice of Clear or Stop on initialisation, not y or yy. So if you have a Dapol signal connected to the TT decoder in the example above, the RM initialisation will send a "Clear" command to address 15, no more, no less than that. If the Dapol signal reacts in a special way to this command, then I am not qualified to answer why that should be.

 

Ray