Opinions on throttle direction changes while moving?

[nkalanaga]

Personally, I'd just as soon have the direction switch locked out if the train is moving.  But I do very little yard switching - no yards!

Reversing while moving is covered in the old copy of the BN Air Brake Handling book I have.  It's under emergency procedures, and is used only if all other means of stopping the train have failed!

[mmagliaro]

Personally, I'd just as soon have the direction switch locked out if the train is moving.  But I do very little yard switching - no yards!

Reversing while moving is covered in the old copy of the BN Air Brake Handling book I have.  It's under emergency procedures, and is used only if all other means of stopping the train have failed!

Yes, I *could* do that.   But what if your direction switch is a toggle?  You flip it, but nothing happens, and now the toggle
is not in sync with the direction of the train.  I could have used pushbuttons, but then that requires more "stuff" - at least
some LEDs to light up to indicate which direction.  The toggle handles all that by being the switch and the indicator.

Honestly, now that I have implemented the slow-down, reverse, speed-back-up scheme, I really like it.
I appreciate people pointing that out to me, because I don't think I would have thought of making it work that way.

Soooo, Peteski, ...
The utility that I use to upload the code to Arduino turns out to be a stand-alone
utility which can be run at a Windows command line to ONLY upload bytes directly to the EEPROM, without disturbing the code. 
That means I could write a user interface for Windows that lets a user make option selections, and have that thing kick off the utility behind the scenes to upload the table to the Arduino.    (or just swipe the utility code and make it part of my user interface, since it is all open-source).  At least there is a relatively easy clear path to making this thing user-configurable, if I ever decide to do that someday.

[NtheBasement]

It is not the throttle - when you select momentum values, the Power Cab actually writes new values into the decoder of the addressed loco's CV3 and 4 using programming on main mode.

This turns out not to be the case.  Ramping the speed up and down is way simpler than reprogramming a consist, no?

Evidence:
Set CV4 to 18.
Set momentum to 5 on the PC, which if the above were true would set CV4 to a value near 128.
Run the loco.
Kill the power.  Turn it back on.
Set PC to program on main.
Check the value of CV 4.  Still 18.

Presumably if both the PC and the decoder have momentum set then the slowest ramping wins.

[Ed Kapuscinski]

First, for Ed's question:
The controller has a switch.  You can run it with or without momentum.  Without momentum, yes, if you wing the dial all the way around to full, your train will go from 0 to full speed immediately.  With momentum on, it will take about 30 seconds to go from 0 to full.
But I don't see what this has to do with errantly (or even deliberately) changing directions while the train is moving.
Are you saying that if momentum is off and the user does this, it should just instantly jerk and change direction?
And if momentum is on, then I could use this scheme of slowing down to a stop, switching direction and ramping back up?

Ah, yes. I think the switch position should do that then.
Maybe a tiny, tiny imperceptible ramp down in direction change, but it should be like "click, change". I think it'll be important for the user to feel like they have direct control.

[mmagliaro]

Ah, yes. I think the switch position should do that then.
Maybe a tiny, tiny imperceptible ramp down in direction change, but it should be like "click, change". I think it'll be important for the user to feel like they have direct control.

I think I agree with this. With momentum off, the slow-down, stop, reverse, ramp-up should be really fast, just enough
"ramp" to keep you from wrecking the train, but quick enough so that if you are switching cars, you don't feel like you are waiting for it.

[Ed Kapuscinski]

I think I agree with this. With momentum off, the slow-down, stop, reverse, ramp-up should be really fast, just enough
"ramp" to keep you from wrecking the train, but quick enough so that if you are switching cars, you don't feel like you are waiting for it.

Exactly. Like, theoretically you should be able to kick cars with it, right?

[peteski]

Peteski:
----------
. . .

"Making user options available" now means you want an interface directly to the computer, like a DCC decoder's CV settings.
I really was not planning on doing that.   I want to keep this thing very simple, with as few controls and variables as possible.

Now... of course, since it is an Arduino that can be plugged into a PC with a USB cable, I *could* eventually write a "configuration" app to run on the PC that would let you tweak a variety of settings and then upload them to the device.  That might be a nifty cool thing to add.... LATER.

I was not thinking about that much of configurability.  I have dealt with many different devices (even as simple as digital clocks, IR thermometers, or even a CATV universal remote control units).  They have different internal settings which can be changed (customized) just by sequences of pressing certain buttons.  Some of those devices don't even have a digital display - only an LED or two (to give you indication like a length of a flash or number of flashes in a sequence to guide you through the programming).  I was thinking of something similar on your throttle to be able to enable.disable to set some features (like momentum or soft-reverse).

[mmagliaro]

Exactly. Like, theoretically you should be able to kick cars with it, right?

You mean like nudge a cut of cars, get 'em rolling, and while you are pushing, hit the reverse so you quickly slow down and back up, and leave the cut of cars rolling away from you?  Yes, I think that would work.
I like your idea.  I stuck it in today and tried it out.  With momentum on, it slows down in 7 seconds, stops for 1 second and ramps back up in 7 seconds (from about half speed).   With momentum off, it is 3 sec, 1 sec stop, 3 sec.   I don't want to push it any faster than that.  From half speed, slowing down to a stop in less than 3 seconds might get hairy if you do it with a 30 car train behind you.

But I will say that the behavior feels a lot more intuitive working this way, which is the goal.  Like you alluded to, the hallmark of a good user interface is that the device doesn't so anything that surprises the user when they push a button. 

[mmagliaro]

I was not thinking about that much of configurability.  I have dealt with many different devices (even as simple as digital clocks, IR thermometers, or even a CATV universal remote control units).  They have different internal settings which can be changed (customized) just by sequences of pressing certain buttons.  Some of those devices don't even have a digital display - only an LED or two (to give you indication like a length of a flash or number of flashes in a sequence to guide you through the programming).  I was thinking of something similar on your throttle to be able to enable.disable to set some features (like momentum or soft-reverse).

I did consider this.  But personally, I really don't like interfaces like that.   It's like those digital watches with 4 buttons that nobody can remember the right hold/push sequence for,  when they want to set the time or the alarm.  I've got a speed dial, two toggles, and two LEDs, and a tactile momentary button for power on/off.  I'm sure I could come up with some combination of that stuff to let the user control the momentum rate.  It could be something like:
. push the power button rapidly 3 times
. wait for red LED to light
. now turn the speed dial to a setting from 0...100 to select the momentum rate
     where 0 is the fastest and 100 is the slowest
. push the power button again to save the setting
. red LED goes out

If you don't push the power button to save within 10 seconds, it cancels and makes no changes.

But as soon as I do that, somebody will want to customize something else.  So not now.  It would be better to
create a data table in the AtMEGA's (Arduino's chip) EEPROM.  For now, it will work how it works.

[peteski]

That's fine Max.  It was just a suggestion.  KISS principle is always good to adhere to.

[Mike C]

KISS principle is always good to adhere to.

  Like Rock n Roll all nite & Party Every Day ?   

[peteski]

  Like Rock n Roll all nite & Party Every Day ?   

O yeah baby!  I'm a KISS fan!  The original band.

 

[peteski]

This turns out not to be the case.  Ramping the speed up and down is way simpler than reprogramming a consist, no?

Evidence:
Set CV4 to 18.
Set momentum to 5 on the PC, which if the above were true would set CV4 to a value near 128.
Run the loco.
Kill the power.  Turn it back on.
Set PC to program on main.
Check the value of CV 4.  Still 18.

Presumably if both the PC and the decoder have momentum set then the slowest ramping wins.

I still stand by my statement.  I knew that the "momentum: button on NCE Power Cab (and Pro Cab) actually programs the CV3 and 4 (POM) on the decoder being addressed by the torttle (or all the locos in advanced consist), but now I actually sat down and verified it. Wasted over 40 minutes.

My Power Cab Firmware Ver. 1.65B  Decoder: Tsunami (in Athearn Big Boys).

First of all, you cannot read CV values on main track (you can only blindly program them).  To read CVs, you have be in programming track mode.

Single loco being tested (not consisted).
Verified (on programming track that CV3 and 4 =0),  then I ran the loco - you can easily tell that no momentum is present.
Set the momentum using the MOMENTUM button on the throttle to 5.  When running it was readily apparent that momentum was enabled
Next on programming track I checked and CV3=40 and CV4=20 (yes NCE does not set them both to equal values, nor to 128).
I killed the power to Power Cab and powered it back on after few minutes.
While I knew what the answer would be, I still first checked on programming track and CV3 was still 40 and CV4 was still 20.
I then ran the loco (Power Cab does retain the last selected loco on the throttle, even after disconnecting power), momentum was still observable.
I then hit MOMENTUM button and set it to 0.  Momentum was gone while running the loco.
Checked on programming track and CV3 and 4 =0.

Basically the behavior was as I expected.
I  then tried in advanced consist with 2 locos.  I controlled the locos by the consist address. Again selecting 5 after pressing MOMENTUM wrote CV3=40 and CV4=20 to both locos (I checked on programming track).  I could also remove momentum from both locos (CV3 and 4 = 0) when I selected 0 after clicking MOMETUM button (verified on programing track).

The MOMENTUM button does a write (on main) to CV3 and 4 of the currently addressed loco  (or locos in the currently addressed consist). No momentum setting is retained in the throttle.

[NtheBasement]

Odd... exactly the opposite of what I observed!  Need one of those packet sniffers.  I've also wondered what emergency stop does if the decoder has momentum set.

[NDave]

From p34 of the Powercab user guide:

THE MOMENTUM BUTTON
When you press the momentum button you are prompted to enter a momentum level. There are 9 levels
of momentum (1-9) plus ‘direct drive’(0). Pressing a digit button from 0-9 will automatically set
the acceleration and deceleration rates of the locomotive(s) being controlled.

Pressing 0 sets the momentum of the train to 0 effectively turning it off. 1 is the smallest amount
of momentum, 9 is the most.

If you are operating an Advanced or Old Style consist setup in the command station all locomotives
will have their momentum set. If an Old Style consist includes one or more Advanced consists all
locomotives in the Advanced consist (up to 6 per advanced consist) will also have their momentum
set properly.

Technical stuff - what happens when you set momentum
The digit entered is multiplied by 8 (factory default) and sent to CV3. The value sent to CV4 is ½
the value sent to CV3. You can change these multipliers.

You can setup the following momentum parameters in the SET CMD STA menu: The acceleration
multiplier can be set to a value in the range of 0-25.

The deceleration can be set to FULL or HALF the value sent to CV3. You can disable the sending of
momentum commands to consists.

If a decoder follows NMRA Recommended Practice 9.2.2 the rates will be as shown below with the
factory default settings (multiplier = 8 and deceleration = half).

Rate 1 = 7 seconds to full speed, 3 seconds to stop
Rate 2 = 14 seconds to full speed, 7 seconds to stop
Rate 3 = 21 seconds to full speed, 10 seconds to stop
Rate 4 = 28 seconds to full speed, 14 seconds to stop
Rate 5 = 35 seconds to full speed, 17 seconds to stop
Rate 6 = 42 seconds to full speed, 21 seconds to stop
Rate 7 = 49 seconds to full speed, 24 seconds to stop
Rate 8 = 54 seconds to full speed, 27 seconds to stop
Rate 9 = 61 seconds to full speed, 30 seconds to stop

If a consist is active when MOMENTUM is pressed the button will do nothing unless “CONSIST
MOMENTUM” is enabled (factory default) in the SET CMD STA menu. Momentum commands will be sent to a
limit of 6 locos per Advanced consist.

Notes regarding momentum commands and decoders:
There are special commands for setting consist momentum (CV23 and CV24) but most decoders do not
support these CV’s.

CV3 and CV4 are required and have standardized values in decoders per RP-9.2.2. Support for consist
CV23 and CV24 is not required in decoders, this is why we use CV3 and CV4 for consist momentum..

Sound equipped locomotives that verbally speak the value of CVs must be turned off by setting CV 62
to a value of 0 for momentum to work properly. Setting CV 62 to a value of 1 turns the verbal
response back on.

Some European makes of decoders require locomotive power to be interrupted
before the new CV vales will take effect.