Modifying the TIU variable voltage output channels to be fixed: Why?

Don,  I have set up my TIU so that all channels are fixed voltage.   I run no conventional DCS or TMCC/Legacy, so I just want the constant voltage on the tracks.   Each of my channels has its own power supply, from Lionel PH-180's

OK, David, but did you have to physically modify the variable outputs to switch them to fixed, did you just use the command from the remote control, or are you running the fixed voltage transformers through the variable output without making any changes to the TIU?

I'm asking this because, as one of the San Diego 3 Railers dealing with the DCS mess on the layout, the explanation I'm getting for them not switching out the ancient TIU to see if it may be defective is that the variable channels have to be modified to run as fixed only before they can use it. Since they're running the TIU with a passive connection now, the issue of whether a channel is fixed or variable seems to be moot point.

 DCS gives you the option of setting up a var channel to var mode or  fixed mode...

Yes you have to set them  with the remote ... Menu/system/ dcs set up/  Select the var channel and hit FXD... The channel is now in fixed mode just like fixed 1 &2 and will stay that way on each power up unless it's  change it back to  var mode with the remote.  The FXD key is like a toggle switch.  With each press it changes the channel from fixed to var with each press. However the remote will tell you what mode you've selected...

The channel will have to be in fixed mode to run  in passive mode.   And of course the channel also needs full power on the input side of the var channel & the tiu need to  turned "on" with power to fixed 1 or an aux power supply. hope this helps.

Menu/ System/ dcs set up/   lot of different options   

The National Capital Trackers have had most of the club TIU's modified to all channels fixed. We do not use the TIU to vary voltage, we use the transformer handle. We use 3 channels on the TIU, the 2 fixed and one variable set to fixed, the variable channel was being reconfigured back to variable and that wasn't being communicated to the next person operating on that track.  In this manner all 3 tracks operate the same now. One benefit of this, is at venues where there is more than 1 club operating, is if another club reconfigures the TIU settings it doesn't impact our TIU. It just continues to operate.

Steve

Don go to track control screen in Barry's book it tell you how to set max volts with the soft keys on the variable channels I did this on a layout with brick's on all of the channels so when they turn on the power everything saw the watch dog signal at the same time and they did have to turn up the power on the variable every time they turn on the layout .

Guy

Sorry I didn't reply to your next question, Don, but the guys above nailed the answer

Another point is if you have the variable channels in fixed mode, simply selecting the track and varying the voltage will revert them to variable mode until the next power cycle of that channel's power.

If I'm reading you all correctly, then, there really isn't any advantage to modifying the circuitry on the TIU to make a variable output channel fixed permanently.  The software control of the output is good enough.

I was typing my reply when you answered, John. So, the variable output can be inadvertently switched out of fixed mode. But cycling the power to the TIU will switch the variable channel back to fixed if it's set in the software that way.

BINGO!

gunrunnerjohn posted:

BINGO!

So, modifying the circuit of the variable output channel to a permanent fixed operation would be advantageous to reducing confusion in a club layout where many different operators are coming and going. I would just put up with having to cycle the power to the TIU myself.  I suppose that if you really needed to have four, idiot proof fixed outputs that using two TIUs in super mode, and just utilizing the fixed outputs on those, would be better than messing with the motherboard on a singe TIU to get four fixed channels.

Clearly, it would be much easier to simply have two TIU's if you're that worried about someone messing the signal up.

DJ's Trains posted:

 I would just put up with having to cycle the power to the TIU myself. 

I was really surprised at how often we had to do that.  Some of our members would unnecessarily power down the entire layout when they just needed to cycle TIU power. We even have a toggle switch for just that. At least for our group it was worth doing. We even had an MTH authorized tech make the conversion.

Steve

Just as an FYI, it would seem to me that the "secret" to improved operation of a club layout boils down to two things:

• Educate all members regarding the proper operation of the layout. This would apply to all club layouts, not just those that utilize commands control. However, command control operation most likely would require that those members who have always operated only in conventional mode would have to "unlearn" some things, as well.
• To keep operation of dual-mode (conventional and command control) layouts easier, I would suggest that the layout utilize the features and functions of the command control system itself wherever possible to allow both conventional and command operation, before adding-on a host of external switches and such to accommodate both kinds of operators.

I'm not worried. I'm just trying to understand the options they are choosing at the SD3R layout. Thanks for the information. 

Barry, Yeah. A lot of the signal issues and other problems stem from the confusing plethora of switches the SD3R layout has for running conventional, DCS, TMCC, and legacy, as well as switching between the power bricks and the Z4K transformers. 

Barry Broskowitz posted:

Just as an FYI, it would seem to me that the "secret" to improved operation of a club layout boils down to two things:

• Educate all members regarding the proper operation of the layout. This would apply to all club layouts, not just those that utilize commands control. However, command control operation most likely would require that those members who have always operated only in conventional mode would have to "unlearn" some things, as well.
• To keep operation of dual-mode (conventional and command control) layouts easier, I would suggest that the layout utilize the features and functions of the command control system itself wherever possible to allow both conventional and command operation, before adding-on a host of external switches and such to accommodate both kinds of operators.

One of the pitfalls of a large club, watch one, run one, teach one. It can be very difficult to get everybody on the same page.

I feel we do a pretty good job of keeping it simple,  a conventional operator places their locomotive on the track, stands at the transformer and operates conventionally, whistle button, raises lowers voltage, the DCS, TMCC/Legacy, LionChief  operator places their locomotive on the track powers up to 18V and goes. Under normal circumstances there is no throwing of toggle switches, changing of wires, etc. The only thing our system isn't set up for is running a conventional with a remote.

Steve

I have never seen this request before, and I don't even know how you modify the TIU for full voltage all the time from the variable channels.  I've never really wanted to do this, so it's never come up.

gunrunnerjohn posted:

I have never seen this request before, and I don't even know how you modify the TIU for full voltage all the time from the variable channels.  I've never really wanted to do this, so it's never come up.

I must be lost on this one.... All our 8 var channels are set to FXD mode. When the layout is power up from   wall switches   all  of  the 8  ZWs come to life along with  every tiu channel.. 16 of them... Single track layout. no loops. No conventional. Don't have to touch the remote.

I run all 4 outputs fixed.  

Gregg posted:

gunrunnerjohn posted:

I have never seen this request before, and I don't even know how you modify the TIU for full voltage all the time from the variable channels.  I've never really wanted to do this, so it's never come up.

I must be lost on this one.... All our 8 var channels are set to FXD mode. When the layout is power up from   wall switches   all  of  the 8  ZWs come to life along with  every tiu channel.. 16 of them... Single track layout. no loops. No conventional. Don't have to touch the remote.

Someone mentioned a hardware modification to the TIU to insure the variable channels stayed in fixed mode, even if you select the track and vary the voltage.  If you read the quote below, maybe my comment will make more sense.  I have no idea how they accomplish this, but it it sounds like they actually modified the hardware.  See the quote below.

L & N posted:

DJ's Trains posted:

 I would just put up with having to cycle the power to the TIU myself. 

I was really surprised at how often we had to do that.  Some of our members would unnecessarily power down the entire layout when they just needed to cycle TIU power. We even have a toggle switch for just that. At least for our group it was worth doing. We even had an MTH authorized tech make the conversion.

Steve

gunrunnerjohn posted:

I have never seen this request before, and I don't even know how you modify the TIU for full voltage all the time from the variable channels.  I've never really wanted to do this, so it's never come up.

This is a requirement insisted upon by a couple of individuals in my club (San Diego 3 Railers), who maintain the wiring on the layout. I can't find any information about this either. That's why I'm asking. I can imagine one would wire a jumper around the component that varies the voltage in the channel on the TIU's mainboard , but this sounds useless if you only run fixed voltage brick transformers on DCS to begin with. The only thing I can figure is that their current configuration allows use of either power bricks or a Z4K transformer to run DCS. And to make it more idiot proof, they hard-wired the variable voltage channel to fixed so that changing the voltage on the Z4K won't change the operational mode of the variable channel.

Actually, the more I'm reading up on this, and the answers I'm getting here, make me think this "requirement" just a lame excuse for not doing anything, like replacing a 13 year old TIU that's probably malfunctioning. 

Ok thanks.. Makes more sense now .    Perhaps in a large club setting to keep unwanted changes??

Gregg posted:

Ok thanks.. Makes more sense now .    Perhaps in a large club setting to keep unwanted changes??

That's the only reason I can come up with. But why not just have the Z4K transformers connected directly to the track and the power bricks connected to DCS? Sounds like less trouble to me. 

L & N posted:

DJ's Trains posted:

 I would just put up with having to cycle the power to the TIU myself. 

I was really surprised at how often we had to do that.  Some of our members would unnecessarily power down the entire layout when they just needed to cycle TIU power. We even have a toggle switch for just that. At least for our group it was worth doing. We even had an MTH authorized tech make the conversion.

Steve

Steve, Out of curiosity, where did your tech find out how to do that conversion?

And, how did the tech get the information on exactly what to mod?

I have done this mod for the NJ High Railers.  It is not hard to do, your just jumpering around the FETs.  You loose Emergency stop features for those var channels, but otherwise it just prevents inadvertent shutdown or cases where a FET goes bad.  G

George, I was wondering about the exact details, are you saying you just basically short out the FET stage?

DJ,

  I run all 4 channels fixed, it gives me all the different DCS options for running all the time.  Including conventional engines from the hand held remote control.

PCRR/Dave

Dave, you're missing the point, the conversation is about modifying the TIU so the variable channels CAN'T vary.  In other words, make them into permanent fixed voltage channels.

At this point I'm only using three outputs, the one variable output is fixed as conventional is extinct on my layout and I don't miss post war stuff at all.

gunrunnerjohn posted:

George, I was wondering about the exact details, are you saying you just basically short out the FET stage?

Yes, Thanks for asking, that's the information missing here.  The details of the modification would be appreciated.

DJ's Trains posted:

Steve, Out of curiosity, where did your tech find out how to do that conversion?

Don,

George (GGG) did the modifications, being that he is a factory trained tech I didn't ask.  One could infer that he learned this in class or has enough knowledge of the circuitry  to have figured it out on his own.

Steve

I'm sure I could figure it out, but it's a whole lot easier to find out how a successful mod was done.

I never removed the cover on one of the modified TIUs to look at what was changed.

Steve

@Gregg posted:

DCS gives you the option of setting up a var channel to var mode or  fixed mode...

Yes you have to set them  with the remote ... Menu/system/ dcs set up/  Select the var channel and hit FXD... The channel is now in fixed mode just like fixed 1 &2 and will stay that way on each power up unless it's  change it back to  var mode with the remote.  The FXD key is like a toggle switch.  With each press it changes the channel from fixed to var with each press. However the remote will tell you what mode you've selected...

The channel will have to be in fixed mode to run  in passive mode.   And of course the channel also needs full power on the input side of the var channel & the tiu need to  turned "on" with power to fixed 1 or an aux power supply. hope this helps.

Menu/ System/ dcs set up/   lot of different options  

Thanks that worked great!

Here is a picture of  the FET's jumpered to create all channels fixed by hard wiring.  As George mentions above, you do loose e-stop on the formerly variable channels.

Steve