MTH 44-Ton Oddity with TMCC

Guess I might need another order then John.

John, do the DCS-RC watchdogs send constantly when powered up?

Stupid question.......

If this is such a big issue, why didn't MTH incorporate the WD circuitry into the TIU? I'm no DCS expert so......

Bob

@RSJB18 posted:

Stupid question.......

If this is such a big issue, why didn't MTH incorporate the WD circuitry into the TIU? I'm no DCS expert so......

Bob

Not stupid at all. My understanding of the TIU is that a channel will send watchdog packets when track power is first applied to the channel. Apparently, the TIU doesn't send them after a short interval.

I was looking at this solution for parked engines thinking I can use one feeder with a DCS-RC to switch in engines. John's experience with this engine makes me think I'll be needing at least two.

@turkey_hollow_rr posted:

John, do the DCS-RC watchdogs send constantly when powered up?

Correct, they connect to the output of the TIU channel and generate a WD every second as long as they receive power.

@RSJB18 posted:

If this is such a big issue, why didn't MTH incorporate the WD circuitry into the TIU? I'm no DCS expert so......

I'm not a mind reader, so I have no idea what was in their heads when they designed the system.  Quite frankly, this amazed me that the Legacy base was causing the issue.

This episode did inspire me to do one mod I was thinking about.  Since I like to test TMCC/Legacy repairs in command and conventional mode, I made a small change to the control of my layout.  I added an RF remote control relay module that allows me to switch off the power to the Legacy base.  Now I can run Lionel command engines in conventional mode without going around and unplugging the command base.  Since I already had a 4-button keyfob that controlled the under layout lighting, I just added the functionality to a different button on the keyfob and used another relay module to switch the power to the command base.  I still have two buttons left...

I'll be adding the WD Generator to the mainline next, as it happens I have one ready to go in my parts cabinet that I kept for a spare.  I guess now I don't have a spare.

@turkey_hollow_rr posted:

Not stupid at all. My understanding of the TIU is that a channel will send watchdog packets when track power is first applied to the channel. Apparently, the TIU doesn't send them after a short interval.

I was looking at this solution for parked engines thinking I can use one feeder with a DCS-RC to switch in engines. John's experience with this engine makes me think I'll be needing at least two.

Correct, whenever the input power comes on for a DCS channel, the WD signal is generated for a sort time.  This is why that initially I supplied a WD for all the tracks except for the mainline.  I've run for months without any issues, but I guess I never actually plopped the 44-Ton locomotive on the mainline and powered up.  It always worked fine if it got driven onto the mainline from one of the other power districts, it's only when it's initially powered and the Legacy command signal is present.  The really odd thing is, since I'm powering up the channel, there should be a WD signal present as well!  Why it needs continuous WD signals is a mystery, but there it is.

@gunrunnerjohn posted:

Correct, they connect to the output of the TIU channel and generate a WD every second as long as they receive power.

I'm not a mind reader, so I have no idea what was in their heads when they designed the system.  Quite frankly, this amazed me that the Legacy base was causing the issue.

This episode did inspire me to do one mod I was thinking about.  Since I like to test TMCC/Legacy repairs in command and conventional mode, I made a small change to the control of my layout.  I added an RF remote control relay module that allows me to switch off the power to the Legacy base. Now I can run Lionel command engines in conventional mode without going around and unplugging the command base.  Since I already had a 4-button keyfob that controlled the under layout lighting, I just added the functionality to a different button on the keyfob and used another relay module to switch the power to the command base.  I still have two buttons left...

I'll be adding the WD Generator to the mainline next, as it happens I have one ready to go in my parts cabinet that I kept for a spare.  I guess now I don't have a spare.

That's a good idea John. I ran into a similar issue when I was recently upgrading my BEEP to ERR. When I first powered it up, it didn't work. I realized that since my Cab1 base was powered on, I had to reporgram the board and re-assign an engine number (I had purchased a used board). The plug for my base is not readily accessible, the RF switching modules are a good idea.

Bob

You have probably already thought about this but it sure seems like there is enough of a transient when the Legacy base powers up to "hide" the watchdogs from the 44-ton engine. But I suppose it could be completely within the engine's firmware as well.

I see the RC boards are still available on the parts site so I'll go ahead and order a couple of them. Please add me to any list you may start for any new orders. I'm in no hurry as I probably won't get to this part of my layout before spring.

Thanks

Piece of cake Bob, and the modules are readily available.  Since I wasn't putting it into a piece of rolling stock, I just used one of the cheap modules on eBay and a 12V wall wart that's switchable with the master power to the layout.  This also has a convenient characteristic, whenever the layout is turned off, the relay resets and the next power-on will have command base power on.

This is one of many such modules on eBay, I used this 433mhz model since I have a bunch of the 433mhz keyfobs handy.

eBay: 132465620812

@gunrunnerjohn posted:

I ran across an interesting issue with the MTH 44-Ton engine.  On my mainline it suddenly doesn't recognize the watchdog from the TIU and as soon as you power up the track, off it goes at warp speed!  I tried several other MTH engines, no sweat, they all work fine on the mainline under the same conditions.  I then tested the TIU, full DCS signals from all channels.

Odd I thought.  On a lark, I killed the Legacy command base, plopped the engine on the mainline, and powered up.  No sweat, it just sat there.  I then fired it up with the remote and drove around the layout, all 10's except a bobble at the DSS switches as it crosses, perfectly normal.  I did the same test with the Legacy command base turned on, and got the same results.

The only time it fails is on the mainline with the Legacy command base on.  On any of the other loops or sidings, it powers up with Legacy powered up no sweat.  Also, if it's on another power district, I can drive it out on the mainline just fine and run.  It's only if it gets a power cycle on the mainline that it drops to conventional mode and then acts like you'd expect if you're in conventional mode with 18 volts on the track, DRAG-RACE!

And now the punchline!

There is one significant difference between the other loops and yards and the mainline.  The mainline does not have one of the DCS-RC Watchdog generators installed on it!  I had figured that since I'd be driving stuff out on the mainline or power cycling it to add an engine, I'd never need it.  That holds true for every other DCS locomotive I have, but for some reason, not for the 44-Ton engine!  I just move the plug for the Watchdog generator over to the mainline track connection and everybody behaved.

Guess what I'll be doing soon...

What is a Watchdog generator?

@DennyM posted:

What is a Watchdog generator?

https://ogrforum.com/...6#157688391364389226

John-

Would the watchdog generator help with restoration after a derail.   I am just bringing up a new layout and have DCS installed and waiting to add legacy until DCS is all working well.

My issues is that if there is a derail, or seems if I stop a large steam loco on a switch, I have to restart everything to get things working again.   Turn off the handheld, turn off the transformers and power cycle the TIUs.

Is this how its supposed to work?   I would like to ideally just set the engine back on the track and then power cycle the 180 brick for the TIU block where the derail occurred and not have to power down the components that seem unrelated.

So LMK if any tricks or if the watchdog generator would help.   If it would do I need one for each of the 4 channels for all my TIUs?

Thx and Happy New Year.

John, do you think you'll be doing another run of the DCS-RC Watchdog generators?

@Stackm746 posted:

I would like to ideally just set the engine back on the track and then power cycle the 180 brick for the TIU block where the derail occurred and not have to power down the components that seem unrelated.

That's all I do even without the WD on that channel.  The only exception seems to be my 44-Ton engine, so now the mainline gets the WD generator.  You shouldn't have to power down everything for a simple derailment or other breaker trip.

@MichRR714 posted:

John, do you think you'll be doing another run of the DCS-RC Watchdog generators?

I just ordered what may be the last of the DCS-RC boards, I got three coming.  So, when I get that order, I'll make up three more complete kits and post them, that'll be the last of the complete kits.  If you can find a DCS-RC, I can still make the trigger boards.

@gunrunnerjohn posted:

That's all I do even without the WD on that channel.  The only exception seems to be my 44-Ton engine, so now the mainline gets the WD generator.  You shouldn't have to power down everything for a simple derailment or other breaker trip.

I just ordered what may be the last of the DCS-RC boards, I got three coming.  So, when I get that order, I'll make up three more complete kits and post them, that'll be the last of the complete kits.  If you can find a DCS-RC, I can still make the trigger boards.

I 'm now committed to watching FS posts for the next month.

@WinstonB posted:

I 'm now committed to watching FS posts for the next month.

Subscribe to the FS forum, you get an email for each new post.

Well, I had to take the wife grocery shopping and I missed out on the RC boards.   I did leave a wish item but I'm not counting on MTH building any more of these. As I posted before I wouldn't be installing one for a while  so if you guys beat me to them that'll be ok. I believe I can still work out a solution with the two unused channels on my TIU. I'm not sure that I would want to continuously switch track power once per second through a channel but toggling once to bring up an engine wouldn't be so bad.

Dan, note that you NEVER want to parallel outputs of the TIU, so using those channels for WD generators may not work out that well.

So after the derailment, and power cycling the 180 brick, the power is restored to the track but none of the engines will respond to startup or any other inputs without cycling both the TIU and Handheld.    Could it be something in the configuration of the TIUs?   If I recall they are setup as a Super something.

@gunrunnerjohn posted:

Dan, note that you NEVER want to parallel outputs of the TIU, so using those channels for WD generators may not work out that well.

Thanks for the warning, I knew that's a no-no. What I'm thinking would be to use one channel wired to a few parking spurs. The sequence would be to shut of track power on that channel, select and engine, then bring the track power back up. I just won't have the constant watchdogs.

Problem solved!  Added a 4th WD Generator to service the mainline and now the 44-Ton engine behaves itself.   Had to squeeze them in a bit tighter from the old layout, but all is well.

It really is an elegant solution. It would be nice if MTH makes more boards, it would be even nicer if they came up with just a watchdog board but that's crazy talk.

It would be pretty easy for MTH to make a WD box, and even easier for them to have an option in the TIU to simply generate the WD every second.  That could be all software.

I think the RCs and John's WD boards are just too nice to hide under the layout. :-) 

Cool display, and the switches I presume are to disable the WD if desired?

Yes. You may recall we discovered that "timing bug" in the iOS version of the MTH remote app that would NOT allow a new engine to be added while the WD Generators are active. The switches allow me to turn-off the appropriate main line WD Generator briefly while I add the engine. 

@gunrunnerjohn posted:

That could be all software.

I thought about that. I also wondered if they were concerned about the life of the generators in the TIU if they committed to the 1 second interval. Another reason to like separate solution.

@turkey_hollow_rr posted:

I also wondered if they were concerned about the life of the generators in the TIU if they committed to the 1 second interval. Another reason to like separate solution.

I can't imagine any component life issue with generating the WD more frequently, it's not like it's mechanics.

Yes, I'm trying to throw them a bone on this one.   It doesn't seem like it was thought through much further than power up.

I think a lot of the more varied situations were simply not considered.  Classic case in point is, of course, sidings and yards.  Having to power cycle the whole TIU channel to bring those up is really not exactly smooth.