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I have one of MTH's latest shays. It works fine under DCS when I power up the layout and the engine sees the watchdog signal from the TIU. The engine comes up in command and operates as it should. However, if it is sitting on a dead siding and I power up that siding the engine takes off at full speed instead of coming up in conventional and not moving. Obviously when powering up the siding there is no watchdog signal for the engine to see but it still should come up in conventional.

None of my other PS2 and 3 engines do this. Its kind of scary to see a shay rocketing off at full speed. Can anyone tell me why its doing this and how to fix it?

Ken

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The watchdog signal is generated when the TIU channel first sees power. If a siding is powered up after this, then engines on that siding will come up in conventional mode.  

True. But,,,,,,,,,,,,,,,why does the locomotive "take off" if indeed it comes up in conventional? All the tracks I had in the engine terminal had toggle switches to turn "on" or "off" the power. Whenever a toggle switch was "turned on", that specific locomotive came up in conventional, but did NOT "take off". Simply using the "start-up" button on the DCS controller then put that locomotive into DCS control.

You can lock a locomotive on a particular direction. If this happens a locomotive can take off off when powered up in conventional mode. This will have no effect on the loco when powered up in dcs mode with the watchdog signal.

A conventional reset should clear the direction lock or use the directions below to turn off the lock.

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Last edited by H1000

GRJ had a fix for your issue with the watch dog signal I used his fix and very rarely have any issues. I have 38 whisker tracks on my turntable and approximately 15 other sidings. The problem I have with my Shay is it will be running and Un commanded the sound will stop and it runs full speed and about half the timer the smoke fan does not work.

Thank you guys for all the suggestions. I figured the engine might be locked into forward but couldn't figure out how it could happen. My layout is command only, powered from a Lionel brick. No transformer with conventional direction, whistle, or bell controls.

Since I had no way to do a conventional reset, I tried a DCS feature reset which didn't work, then a factory reset. That worked and now the engine comes up in conventional and does not take off when powered up on a dead siding.

Problem fixed but I still don't understand how it got locked into conventional forward.

Ken

The watchdog signal is generated when the TIU channel first sees power. If a siding is powered up after this, then engines on that siding will come up in conventional mode.  

So the watchdog signal is pretty much the TIU doing a "role call" on what is on track? So if the supported engines are on a section of track not powered during that "role call" it will assume it's not present.

The watch dog just tells every DCS equipped engine on the track to power up in DCS mode and not in conventional mode, hence all engine that see the the signal will power up dark & silent. If a DCS engine is powered up but does not receive the Watch Dog, it will come up in conventional mode with lights and sound turned on.

A "Role Call" is when you perform a READ and all engines report back to the remote or app so the controller knows what engines are active.

Last edited by H1000

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