Off the top of my head, I'd have the DCS locos sitting on a siding electrically disconnected from DCS when it's powered up so they don't see the "watchdog" signal that would otherwise tell them to come up in command mode. Then switch on power to the siding and the loco/s should come up in conventional (reset) mode.

 

There are probably other ways, but I haven't run into that situation often. I just bridged the power inputs between fixed and variable 1, then hooked up a switch box to send either fixed DCS or the variable channel to the track. I don't recall trying to run any DCS engine in conventional since I got the system though.

 

---PCJ

Easiest way I have found is to move them to a siding or yard that has a toggle switch to power off the track. Once moved to this area power down the track and then run the conventional. You can also power down the DCS engines individually, or start them up with the DCS and they will remain stationary while you run conventional. No way I know of to stop a conventional from taking off when you power up in DCS, unless loco was shut down in neutral on prior session or it is parked on a dead track 

 

There are quite a few threads on this on the forum. 

So, if I power down the DCS engines individually, they will remain stationary while I run conventional?

I will need to change from variable to fixed via the handheld, while keeping my wires attached to variable 1 on the tiu correct?

Incorrect I think.

 

If you power down the DCS engines (PS2 engines are all I have) then apply power to the track to run conventional, the DCS engines will also move (in conventional mode), at least that's the way I see it.

I just tried this.  I was running a conventional (Locosound) 2-8-0 and powered down (leaving the 2-8-0 on the track) and put my NW2 (PS2) engine on the track.  When I powered back up I heard relays click in both engines.  When I advanced the throttle the 2-8-0 moved while the NW2 did not.

 

Even though I haven't tried it, if I powered down and brought the system up in DCS mode I'm pretty sure the 2-8-0 would scream down the track due to the full voltage being placed on the track.

 

You need to ELECTRICALLY isolate (i.e. turn off) the track a DCS engine is sitting on, usually done with an ON/OFF switch, to run a conventional engine.  If you want to stop the conventional engine and run a DCS engine you need to park the conventional engine on a siding and ELECTRICALLY isolate (i.e. turn off) the track the conventional engine is now sitting on.

 

Here's a procedure I wrote to switch back and forth between DCS and Conventional engines (at present I take the engines off the track so there's no way they can start up when I don't want them to.  Soon I will isolate a couple of sidings so I can leave the engines on the layout).

 

I use a Z-750 transformer/brick for my power supply, connected to VAR1 INPUT and jumpered to FIXED1 INPUT, with VAR1 OUTPUT going to the track:

 

 

Switching From DCS/PS2 Engine To Conventional Engine And Back

 

Changing From DCS/PS2 Engine To Conventional Engine

 

1. With TIU and Handheld Remote OFF, place Conventional engine on track
2. Turn Handheld Remote ON
3. Press TR button
4. Select 1:TIU1 VAR1 with Thumbwheel.   Screen should display:          VOLTS:0.0 TIU1 VAR1
5. Turn TIU ON
6. Rotate Thumbwheel so screen reads:          VOLTS: 5.0
7. Press DIR to put engine in FWD
8. Roll thumbwheel to control speed of engine

 

Changing From Conventional Engine To DCS/PS2 Engine

 

1. With TIU and Handheld Remote OFF, place PS2 engine on track
2. Turn TIU and Handheld Remote ON
3. Press ENG
4. Select the PS2 engine that you want to control from the menu
5. Press STARTUP
6. Roll thumbwheel to control speed of engine

This procedure works for me, but it is not exactly what Barry Broskowitz (our resident DCS guru) said in a post not too long ago:

is there a way for MTH DCS engines to not start up in conventional mode while on the track when running my conventional locos and vice versa when in DCS mode.

As long as a DCS engine receives power at the time when power is applied from the output of a TIU channel, there's no reason for it to come up in conventional mode at all, unless one of the following occurs:

• Power is applied too slowly and the DCS engine's electronics are not sufficiently "awake" to sense the watchdog signal before it's gone
• The DCS engine is powered up after the channel is powered up, i.e., power is switched on via a toggle switch
• The DCS signal has been turned off for the engine's channel via the DCS Menu.

Barry, I thought that if the input to the channel was powered and you just switched the track power on that you wouldn't get the watchdog.  Are you saying that the DCS channel senses when a load is presented and resends the watchdog signal?  What's different about that than just switching on a non-powered track, I know those come up in conventional.

I just edited my post above.

John, Re-read my post. That's not what happens. What triggers the watchdog signal is when a TIU channel's output voltage changes from 0 to any other value. However, if the voltage goes up too slowly, the DCS electronics may not sense the watchdog, causing the engine to go into conventional mode.

OK, I thought he was switching the output track on with the voltage already at a value.

Barry,

Did you or do you work for MTH or are a service dealer?

How did you learn so much about DCS?

Your knowledge is amazing!

Did you or do you work for MTH or are a service dealer? How did you learn so much about DCS?

Ten years of beta testing DCS.