Friday, May 27, 2016

A Few Words about the 21 Pin Decoder Interface and an Interesting Afternoon

The 21 Pin Decoder Interface

Here is a well written report which backs up my ongoing dislike of this 21 pin decoder interface debacle and the growing use in Australian locomotives by some of our manufacturers.

The only locomotive (Auscision 45 Class) I have bought that had this connector no longer has it.
The other aspect of 21 pin decoders that I don't like is that they are restricted to 4 outputs for lights, not enough by any stretch of the imagination.

An Interesting Afternoon

Linton Towelly visited Bylong yesterday afternoon with his latest ESU Loksound 4 diesel sound project loaded into a 442 Class. In my opinion Linton has taken a more sensible approach to the problem of notching in diesels.

As you may know, ESU has just announced a diesel sound flow template called ‘Full Throttle’ which attempts to replicate notching but which requires the use of about 4 more function buttons to achieve this. Given that most existing cabs have perhaps 8 or 9 function buttons available conveniently and that a number of these are relatively ‘standard’ it seems inevitable that the use of the higher number function buttons will be required, hence the awkwardness of using it. Of course, I have previously referred to the manual notching of ESU Loksound 4 diesel sound flow templates as playing a musical instrument and I believe now that with ‘Full Throttle’ the instrument has become a piano.

One good aspect of the ‘Full Throttle’ sound template is that it now has a working brake.

Now back to Linton’s sound flow template. Linton downloaded the new ESU ‘Full Throttle’ sound template for an EMD 645E for his NSWR 422 Class and then proceeded to remove the diesel motor sound drive flow chart that controls the notching but retaining the other aspects such as the braking.
Linton has previously produced a sound flow template for a XPT which has only 5 notches.

Expanding and modifying this template Linton has produced an eight notch template as used by most diesels. When Linton deleted the sound flow for the motor drive this action didn’t delete the sound files of the motor so he was able to use these in his motor sound drive flow.

The end result is very nicely implemented and although I haven’t driven a diesel (Linton used to drive them) I feel that his implementation seems to be much more like the real thing than the new ESU ‘Full Throttle’.

Now how does it work?

When the throttle is increased the diesel motor sound starts to notch up and will continue to notch up until it reaches notch eight unless the throttle setting is reduced by 1 speed step at which point it will hold at the particular notch running when this throttle adjustment happens. If the throttle is then reduced again by 1 speed step the diesel motor will start to notch back down. If the speed step is increased the notching will increase to the previous level and another speed step increase will have the notching increase again until of course it gets to notch eight. Now keep in mind that this may happen at very low speed steps, e.g. 2 or 3 which means that the loco can be put into notch eight while hardly moving (heavy train). The same actions at higher throttle speed steps can produce the same effects meaning that once moving at a good speed the throttle can be reduced slightly and the diesel motor sound will drop back into a coasting phase. All this can be achieved without hardly changing the actual moving speed of the locomotive and just by using the throttle, no function buttons to remember, find and press for different aspects of the ESU ‘Full Throttle’ implementation.

I should have taken a video of the 422 in action going up and down the 1 in 40 grades on Bylong with a full train but I was having too much fun driving it and didn’t think of doing a video. Linton designed this motor drive sound flow chart using 28 speed steps but tests on Bylong showed that it also worked on the 128 speed step range of the throttle.

For those who haven’t seen the videos, here are two videos that Linton posted on a couple of Facebook groups recently in which he explains what he has achieved. You may need to turn up the volume a bit.

I hope that I have explained the way Linton’s notching works correctly but I think that you will get what I mean after watching the videos.

Part A:

Part B:

In the Part B video there is also an explanation of how Linton has the dynamic brake working, very nice. The dynamic brake doesn’t actually brake the locomotive speed though but it does go through all the sound changes that the real diesels do, of course the working brake could be used to replicate some actual braking I guess.

Overall a very enjoyable and interesting afternoon with Linton.