TCS - Train Control System Decoders

Note: this page is under construction, some products are here, and some have their own sub pages.

The UWT-100 throttle is at the bottom of the page.

The TCS WowSound 501 Large Scale decoder is here: TCS 501 decoder

Overview

TCS makes a lot of stuff, I won't cover it all.

I've found fundamental bugs in their decoder firmware, read below, and the first WOW sound & motor decoder had lots of bugs.

Personally I run Z and G scales, and custom speed tables are a must, for consisting, and my own preference to map speed steps to actual scale speed.

I was unable to get around the severe bugs in the Z scale decoders. It's not such a big deal in G, but I will check our my newly-upgraded Wowsound 501 to see if all the bugs I found were fixed.

Enough on the negative stuff, I will put details at the end of this page.

TCS Z scale decoders

TCS makes several mobile decoders, the AZL4 drop in for many AZL locos, the MZA4 drop in for many MT locos, and the Z2 wired decoder for hardwired installations.

As an overview, many people like these decoders because they have 4 lighting outputs (the standard headlights and 2 more) so for extra lighting it's nice to have.

They also make 2 function only decoders, the FL2 and FL4.

My biggest gripe is the custom speed table. A bit of background: very few people use a custom speed table. Usually Vmin, Vmax, and Vmid (if implemented) is sufficient.

Many people complain about different speeds of locos at the same Speed Step, but don't do anything about it, and it's easy with the above settings.

I've used speed matching in G scale for a long time, since I run mainline trains with multiple locos on a train more often than not.

In Z scale, there is a VERY wide variation in speeds, due to different gearing, and something more common in Z scale, identical locos will run at different speeds, due to small differences in friction, mechanicals, etc. It's just a fact of life in this tiny scale where a cat hair on an axle makes a big difference.

So, I use custom speed tables, where you get 28 different values for "voltage" at each speed step. Suffice it to say in 128 SS mode, different manufacturers do different things, some do not support custom speed tables in 128 SS modes (stupid, mostly old designs), but most modern ones do, and interpolate the speed from 28 to the 128 steps.

Suffice it to say here that TCS decoders are crap (yes this adjective/noun is deserved) in this respect, the short answer is that there are 2 symptoms, both I think of a common issue internally.

1. setting a progressive set of entries does NOT give a progressive set of resulting speeds.

2. modifying certain steps in the custom table can produce wild and unpredictable results.

I'm stopping here, to finish later, and fill in the details, and how you can demonstrate this for yourself. I also need to check out the G scale decoder and see if it has the same problem.

My version reported from CV7 is 49.

MZA4

The picture below shows the MZA4. This is a drop in decoder for the MT GP9, GP35, and SD40. There was a "recall" where there was copper very close to where the motor springs go. This copper was connected to the circular "land" that the chassis "pins" connect to, thus creating a short between the motor and the track pickups. Don't know the dates on this. http://www.tcsdcc.com/Customer_Content/Technical_Info/Tech_Info/FAQPage.php?q=64

The solution is to cut/grind away the little chunk of copper in the picture (or you could use kapton tape it seems)

There are 4 functions, counting the two headlights. There are 3 pads to support the 2 extra function outputs. In addition, they indicate the location of the current limiting resistors for the 2 stock leds.

Z2

The Z2 does not have the extra 2 solder pads for the extra 2 functions like the drop in.

TCS Version information:

CV 7 - version number (does not work on my wowsound)

CV 8 - mfg ID (153)

CV 248 - sound set version (wowsound only??)

CV249  - decoder type (wowsound only according to manual) but seems to have the following values:

FL2 is 6
FL4 is 7
MZA4 is 40
Z2 is 41
I got 172 from the WowSound diesel, don't know if this is right or not.

CV250 - month of f/w programming

CV 251 - day

CV 252 - year

(note on the WowSound, the audio readout of this date matched what was in registers 250-252)

BEMF

Many people have performance issues with BEMF enabled.

Years ago, general counsel was to turn off BEMF when consisting, not sure this is still true for all manufacturers

BEMF is enabled by default, It seems that you cannot disable BEMF on WowSound

CV182 has some interesting BEMF features..

bit 0 - automatic bemf / stop on dc enabled / no keep alive

bit 1 - set for special bemf for 3 pole motors

bit 2 - automatic bemf - stop on dc disabled / keep alive enabled,  this is set by default..

bit 3 - disable safety check (need function packet received twice to act on it) (wowsound)

bit 4 - approx 2 second motor delay (wowsound diesel)

TCS complete CV function list:

The "manual" supplied with the decoders, well, it basically "sucks" in my "DCC" opinion. I've seen this where there is a "starter" manual, kept short to avoid confusion, then more manuals for more advanced topics. I am firmly against this, it creates confusion, either by omission of information or the pain in the butt managing multiple documents and where to find what. Make a single manual with the "getting started" in the beginning.

I'm creating a single list here, because some are not listed, and many are listed in a confusing way, and some are on separate documents.  Here's my cheat sheet and comments.

Things in bold are stuff that is "different" or "interesting".

CV 1 - short DCC address (default 3)

CV 2 - start speed, (default 0)

CV 3 - acceleration momentum (default 1)

CV 4 - deceleration momentum (default 1)

CV 5 - top speed (default 0)

CV 6 - mid speed (nice) nice (default is 0, straight line between CV 2 and CV 5)

CV7 - decoder version

CV 8 is decoder reset, set to 2 for reset, resets most stuff. Read back for manufacturer id, should be 153 for TCS

Factory reset can be done on the main track or on the programming track. To reset CV's to their factory setting write a value of 2 into CV8. The reset occurs the moment the decoder gets the reset command. (Earlier decoder versions had to go through a power on/off before the reset occurred.) CV's that will reset to factory default: 1, 2, 3, 4, 5, 6, 17, 18, 19, 29, 30, 49, 50, 53, 54, 55, 56, 57, 61 . The user-loadable speed table is not affected by the reset

CV  10 sets BEMF cutout speed

defaults to 0, i.e. BEMF always on... range is almost exactly mapped to speed steps, so if you want it to cut out at ss 10, set to 10. This might be helpful in consists.

CV 13 - analog power control "turn off black or red powered functions"

analog power conversion (DC mode) must be enabled in CV29... also refers to "brake on DC". Apparently if the loco crosses from DCC into a DC "block", the loco will slow to a stop (subject to CV4 setting), "convert" to analog power, and then accelerate to  a speed appropriate to the DC voltage level. Weird, but I think some of this is legacy stuff for when DCC was young. (Thanks for the explanation: Garth Hamilton) default is 255, don't know what different values do.

CV 15 is decoder lock

to unlock set to zero or equal to CV16, setting CV 15 to 7 locks all decoders that are at same address, same address decoders need different CV16 subaddress.  (I guess this implies POM)

CV 16 works with CV 15

convention is to set to a number for groups, can be set to anything apparently, see the manual for a confusing explanation, but =1 for mobile, =2 for sound, =3 lights only as defaults, you can set it to anything if you want a unique lock.

CV 17 & 18 - standard long address registers (default 0)

CV 19 - standard consist address register (default 0)

CV 21 - consist lighting control - affects function output wires, green, purple, brown wires in a consist. (only green and purple on Z2)

green is 1, purple is 2, brown is 4. add them in if you want them active in consist.

CV 22 - consist lighting control - headlight/white wire = 1, rear headlight/yellow wire = 2, set these for active in consist as in cv 21

so lead loco wants cv22 =1, rear loco wants cv22 = 2

Note: there is something erratic in this programming, had to program locos several times for it to work right, even though reading CV22 gave the right result. Also seems that changing any other lighting configuration wipes this setting out.

CV 23 & 24 - standard acceleration and deceleration in consist (default 0)

CV 29 - follows standard (default 6) Note that 28 speed steps and DC mode are the default, the manual is really backwards, implies 6 means 14 steps and disable DC mode

bit - value - meaning when "on"/set

0 - 1 - reverse direction (default forward)

1 - 2 - enable 28 speed steps (default)

2 - 4 - enable DC mode (default)

3 - 8 - enable railcom

4 - 16 - activate loadable speed table (default use standard speed table)

5 - 32 - enable long address (default short address enabled)

CV 49-52 control the lighting effects for the outputs for white, yellow, green, purple respectively. (white and yellow are front and rear lights) (note Z2 only has white and yellow)

set to 0 through 13 for front light only, add 16 for reverse light only , add 32 for both - see their table http://www.tcsdcc.com/Customer_Content/Literature/Decoders/Z_Scale/MZA4/MZA4_WEB.pdf

CV 56, 57, "dither" frequency and voltage - when enabled, it is enabled all the time. (defaults 3 and 10 respectively)(enable with cv 61) (My opinion is the TCS BEMF is fine, even in consists)

Like "kick start" in NCE, only works if BEMF is off. Both need to be greater than 0 to be working.

56 is frequency, default is 3, 1 is highest freq, 255 is lowest

57 is voltage, default it 10, lowest is 1, highest 255

TCS recommends using dither of 15 as a starting point, and increase by 5 at a time until you get proper low speed starting. Then play with frequency by 1 at a time to see when it improves.

CV 61 - BEMF control and dimmed lighting (default 1, BEMF on, no dimming)

bit - value - meaning when "on"/set

0 - 1 - enable BEMF (always active on WowSound)

1 - 2 - enable function button control of BEMF (won't come on unless bit 0 is 1) (default is function key 6) (always active on WowSound)

2 - 4 - maybe enhanced button control, auto control - f2 on/off, direction for reversing

3 - 8 - button control of braking (trolley)

4 - 16 - enables headlight dim when stopped (rule 17 enabled)

5 - 32 - enables the "opposite" light dimmed (rear light dimmed in forward)

6 - 64 - maybe used in button control of motor output (f2 forward, f3 reverse)

? - 68 - ??? WTF ?? Automatic Button Control of motor (looks like this function is really bit 6 and bit 2)

7 - 128 - button control of brake lights (trolley)

CV 64 - sets dimmed brightness

2-6 for LEDs, 12-18 for bulbs. Default is 15 - need to experiment

CV 67-94 (custom speed table)

note: seems you have to do this in service mode, not pom

CV 105, 106 - user registers

CV 125-132, supplemental acceleration curves "variable momentum", that "enhance" CV3 and 4. (not sure these are implemented)

For acceleration, cv 129 - 132 take over from CV3, cv 129 is the rate 2 starting point, and cv 130 is the rate 2 acceleration, cv 131 is rate 3 starting point, and cv132 is the rate 3 acceleration.

Similarly, cv125 and 126 are the rate 2 "pairs" for rate 2 deceleration, and cv127 and 128 are the rate 3 pairs.

CV 136 - sets which function button can turn BEMF on and off

Default is 6, but this is off by default in CV 61 (bits 0-7 correspond to functions 5-12, 1=5, 2=6, 4=7, 8=8, 16=9, 32=10, 64=11, 128=12 (very weird)

CV 248 - sound set version (wowsound only??)

CV249  - decoder type (wowsound only according to manual) but seems to have the following values:

FL2 is 6
FL4 is 7
MZA4 is 40
Z2 is 41
I got 172 from the WowSound diesel, don't know if this is right or not.

CV250 - month of f/w programming

CV 251 - day

CV 252 - year

(note on the WowSound, the audio readout of this date matched what was in registers 250-252)

Tips / Problems:

Speed control:

I noticed that if you set CV 5 or CV 6 to anything other than zero, then the speed of the loco does NOT increase with increasing speed steps, but has a "glitch" approximately ever 4 speed steps.

If you set cv 5 nonzero, and then step up from SS 0  by increments of 1 SS, (use 128 ss, it's easier to notice) you will hear/see the loco increase speed with every step, except at the "glitch points", where increasing the speed by one step actually results in a lower speed than the previous step.

The glitches I noticed were at SS 5, 9, 14, 18, 23, 27, 32, 36, 41, 45, 50 (did not bother going higher)

I found this out because I was working on a different problem, in a Marklin Mikado, increasing the speed near max, results in a runaway at full speed, uncontrollable. It appears the motor noise masks the ability of the decoder to receive commands.

By setting CV5 to about 70, this tendency was almost completely eliminated, and when the "runaway" occurred, usually a second speed command brought it back.

I surmise the first problem above is caused by bad coding, a math error in the firmware. Thus I reasoned a custom speed table would solve the "speed step glitch". It did.

The problem has been noticed by many people, although the "loyal" followers will deny it, often stating they have installed "dozens" and never seen the problem.

Here's a link to a discussion and description of the issue:

https://www.therailwire.net/forum/index.php?topic=40182.0

Apparently a TCS rep acknowledged the problem in October 2016, so maybe we will have some resolution.

 The stuff below is messed up, will fix as I finish the CV table and incorporate it.

advanced consisting and cv21 and 22

make sure all lights are off before doing any programming

More on the decoder:

There is a self repair option in version 4 and above firmware.

From Dan at TCS:

The short explanation of this error is that the decoder detected multiple communication failures between the sound processor and the SD memory card, or corruption within the SD card itself or issues with the controller within the SD card. If you want the long answer, let me know. TCS recommends returning the decoder for service under our Warranty Program to correct this issue.

There is a “self-healing” option available in Version 4 and newer Diesel decoders which can sometimes repair this issue. To run the repair code for this error, go into Audio Assist, navigate to the factory reset menu, and then button number 7 five times rapidly. The audio will cut out completely for a few minutes as the repair takes place. Eventually, the decoder will reboot and the error should be fixed. If the decoder takes over an hour to reboot, contact us - further action may be required at that point. If the decoder does not go mute, but continues to play Audio Assist messages, the repair is NOT RUNNING, and either needs to be re-attempted, or decoder returned for service (does not support the repair function).

Internally, our repair process for this is simple - the decoder will be updated to the latest software and a new SD card installed. An upgrade fee may apply, depending on whether or not your decoder hardware is still maintainable/update-able.

TCS UWT-100 Throttle

New in 2021, a small, universal wireless throttle with an LCD screen. This section is incomplete, but I will fill it in more. Not all the information is easy to find, for example the "manual" seems to be a WiKi, there is a quick start guide. Nowhere could I find the size of the loco recall stack, for example.

This is a good idea to allow people to standardize on a powerful throttle no matter what system they are using. How this fares depends on how much each DCC system "reveals" in terms of external commands.

• Uses Wi-Fi
• Has 4 speed up down buttons and a roller wheel just like NCE
• uses 2 AA batteries
• comes with wrist strap, a nice feature, the connection loop can have a lanyard attached (my preference)
• entering letters is assisted with the thumbwheel, a nice idea
• the throttle interfaces to:
  • Digitrax LNW1
  • MRC
  • WiFi Traxx
  • JMRI
  • LCC??

Pro's

• slim design convenient
• interfaces to different protocols
• firmware updated via Wi-Fi and Internet
• If using JMRI, you can scroll through roster on screen
• backlit
• function labels (4 top buttons) updated by JMRI
• in throttle consisting (assuming this is basic consisting)
• recall up to 20 locos (need to verify)
• built in flashlight

Con's

• expensive, $300
• other than speed controls, no labelled buttons
• no clock on display
• throttle only displays 128 ss mode, even if you are in 28 or 14 SS modes
• scattered and incomplete documentation

New user suggestion:

I was recently corrected that the loco recall is no longer 2 locos but 20. Apparently this was documented in a firmware release note.

My suggestion is that you may have to keep your own notes on things in one place or document as the system documentation is scattered.

First of course, read the quick start guide... not much there but start there:  https://tcsdcc.com/sites/default/files/2020-02/UWT-100%20Quick%20Start%20Guide.pdf

Then I would suggest reading the complete wiki: http://docs.tcsdcc.com/wiki/UWT-100

But, unfortunately, not everything is there, so you should read all the release notes on this page:  https://tcsdcc.com/firmware