Clinic 2014 Lee Ryan DCC Advanced topics

Digital Command
Control
Demystified
By Lee Ryan
Why go DCC?
As a DC owner/operator, would you like any of these features when
operating your trains on your personal or club layout?
-Easy individual loco control
-Operation more typical of the prototype
-No block controls and no more “Who's got my train”
-Easier wiring
-Better motor performance by tuning your locos
-Walk around capability
-Sound in your existing locos.
-Light effects that can be selected off/dim/on at a constant intensity!
Can also be on when the loco is stationary.
Do you want to operate trains and not your layout?
Advantage to Digital Operation
•Component Standards – NMRA Conformance
•Large product selection
•Secure investment – upgradable
•Large base of support
•One technology for multiple scales
•High functionality:
Speed Control – Lighting – Sound – Accessories
•Full voltage – Uses existing layout wiring – Can
operate one analog locomotive (not recommended).
•Multiple locomotive operation with multiple users on
the same track
Components of DCC Systems
•Cab / Throttle
•Command Station
•Power Supply
•Power Station (Booster)
•Mobile decoder
•Accessory decoder
Cab / Throttle
•Controls locomotive speed, direction, lighting, and
sound functions
•Tethered, wireless, and built-in to the command station
•Multiple throttles per 1 system for multi-operator ease
Wired / Wireless: $90 – $250
Command Station
•Brains of the DCC system – generates the
information decoders use to operate your locomotive
•Each system needs just one command station no
matter the size of the layout
Power Supply
NCE P515
5 Amp power supply
Input: 120VAC
Output: 15VAC, 5 Amps
NCE Brutis
10 Amp power supply
Input: 120VAC
Output: 18VAC, 10 Amps
MSRP:
$169.95
MSRP: $59.95
Digitrax PS 2012
20 Amp power supply
Input : 120VAC
Output: Selectable: 13.8, 18, or 23 VAC
Can power four 5 amp boosters
MSRP: $179.99
Power Station (Booster)
•Amplifies the digital signal to the rails
•Built-in to the command station most often
•Some provide short circuit protection, voltage regulation, and
auto-reversing capabilities
SB5 for use with NCE PowerCab only!
MSRP: $219.95
NCE PB5 (updated PB105) same box
Incl. P514 5 amp power supply. MSRP: $199.95
Digitrax DB 200+ 8 amp booster
Power supply not included
MSRP: $199.99
Mobile Decoders
•The brains for the locomotives
•Connects between the locomotive motor and the rails
•Receives the digital signal from the command station and
translates (decodes) the signal into visual or audible effects from
the locomotive
•Uses a unique address to identify it amongst multiple locomotives
– user assigned – usually the cab number
Non-Sound: $10 - $40
Sound: $100 - $140
Speakers: $10 - $15
Accessory Decoders
•Similar to mobile decoders except that these are
stationary around the layout
•Used for controlling line side items such as track
switches, signals, turntables, lighting, or anything you
wish to animate
Prices range from $20 - $75
for standard switch control
Signal components are
$50 - $125
How the Pieces Work Together
1) The user adjusts the Cab / Throttle settings, which are sent to the
command station.
2) The command station then transforms the data into a digital packet
which is amplified by the booster and sent to the rails.
3) The decoder receives the information packet and decides if the packet
is addressed to it or if it is meant for a different decoder.
4) If the information packet is intended for the decoder, it processes the
data and changes a visual or audible effect on the locomotive. This
includes motion, lights, sound effects, etc.
5) If the information packet is not intended for the decoder, it ignores
the data and continues doing what it was doing for the locomotive it is
installed in.
DCC Track Signal
•Bi-Polar DC Signal
•Full voltage 100% of the time
•Each cycle encodes a data bit
•Pulse width encodes a “1” or a “0”
(Stretched “0” for DC loco on DCC)
•8000 bits per second
•Multiple bits make up a data packet
DCC Decoder Information Packet
Information (Data) packets consist of 4 basic parts
*Preamble
*Address
Byte
*Instruction
*Error
*200
Byte
Detection Byte
data packets are sent each second
Measuring DCC Current and Voltage
Cannot use standard multimeter
Root Mean Square
(RMS) Multimeter
Root Mean Square
(RMS) Oscilloscope
FLUKE 87V $399.95
FLUKE 179 $299.95
Tenma 72-8474 $949.99
Tenma 72-8470 $699.99
RRAmpMeter III $104.95
Same as II with battery backup for
measurements below 7 volts
--------------------------------------------------------------------
RRAmpMeter IV HP $124.95
Same as III - for large scale high voltage
and current applications
DCC: 38.6 volts and 18-20 amps
AC: 27.6 volts and 18-20 amps
DC: 38.6 volts and 18-20 amps
RRAmpMeter I
$64.95
RRAmpMeter II
$94.95
Terminology
•Lots of jargon and acronyms
•DCC Ready vs. DCC Equipped
DCC Ready means the locomotive is “ready” for a decoder. Its
motor is isolated from the track through a circuit board. The
circuit board may have a plug (8-pin or 9-pin) for easy decoder
installation. Others require replacing the factory circuit board
with a similarly shaped and sized DCC decoder.
DCC Equipped means the locomotive is “equipped” from the
factory with a DCC decoder. Place on a DCC layout and have fun.
Some factory installed decoders are pre-programmed to the last
2 digits of the cab number. Others are default to address 3.
Decoder equipped locomotives can be operated on analog DC.
Sound Equipped locomotives are automatically DCC Equipped!
Configuration Variables
•Configuration Variables (CVs) are used to make
changes to parameters within decoders
•NMRA Standard CVs
•Manufacturer specific CVs
•Numerous CVs available for use – not all are used
•Some CVs have multiple ‘levels’ and control many
different parameters – Indexing
Changing CVs
There are two methods for changing CV
settings:
•Service Mode Programming –
Program track
•Operations (Ops) Mode Programming Main Operating Track
Service Mode Programming
•Uses a separate track called the ‘program track’
•Requires an isolated section of track – can be a dead end
siding with a Run / Program toggle switch
•Can read CVs back with most systems
•Do not need to know the locomotive address
•Cannot test settings changes in Service Mode
•Program track booster required for some sound decoders
•Some systems may have difficulty reading or programming
other brands of decoders
Operations (Ops) Mode Programming
•Also known as “Programming on the Main (POM)”
•Reliable
•No need for a separate track or to shut down the layout
•No need for programing boosters for sound decoders
•Can test settings changes immediately
•Cannot read CVs
•Must know the locomotive address
•Each locomotive on the main needs to have a different
address OR locos programmed individually
•Multiple locomotives can get programmed accidentally
What is a Configuration Variable?
(Warning - Technical Jargon)
• To humans a numbered information slot
• Really a computer byte which means it is 8 bits
• A bit is a simple 0 (off or ‘low’) OR 1 (on or ‘high’)
• Bits in the bytes are numbered from right to left
• First bit is called bit number 0 on the right
• Last bit is called bit number 7 on the left
• Each higher bit has double the value of the previous one
• 76
• 00
00
00
00
00
00
00
01
11
5
0
0
0
0
0
0
1
1
1
4
0
0
0
0
0
1
1
1
1
3
0
0
0
0
1
1
1
1
1
2
0
0
0
1
1
1
1
1
1
1
0
0
1
1
1
1
1
1
1
0
0
1
1
1
1
1
1
1
1
=
=
=
=
=
=
=
=
=
0
1
1+
1+
1+
1+
1+
1+
1+
2
2
2
2
2
2
2
=
+
+
+
+
+
+
3
4=
4+
4+
4+
4+
4+
7
8=
8+
8+
8+
8+
15
16 =
16 +
16 +
16 +
31
32 = 63
32 + 64 = 127
32 + 64 + 128 = 255
• A CV value cannot be higher than 255
• Can take any value between 0 and 255 (256 possibilities)
• CVs can be used to:
Store a unique configuration item (CV 1)
Store part of a configuration item, larger than 255 (CV 17 & 18)
Store many configuration items (CV 29)
7 6 5 4 3 2 1 0
128 64 32 16 8 4 2 1
Important CVs
CV 1 – Short Address
*Decoder’s Primary Address (ID)
*Range is 1 to 127 - (bit 7 not used by DCC norm)
*Usually set to the last two digits of locomotive cab
number
*CV 1 is almost always set to 03 from the factory
*Some Atlas locomotives CV 1 is pre-programmed to
last 2-digits of cab number
Important CVs continued
CV 17 & 18, Long Address
*Range 1 – 9999
*Two CVs needed
*Often set to locomotive cab number
*Can be set manually - (back door programming)
DCC Extended (4-Digit) Locomotive Addresses Using CV17 and CV18
Range of Addresses
Range of Addresses
Range of Addresses
From
0
256
to
255
511
CV17
192
193
From
3584
3840
to
3839
4095
CV17
206
207
From
7168
7424
to
7423
7679
CV17
220
221
512
767
194
4096
4351
208
7680
7935
222
768
1023
195
4352
4607
209
7936
8191
223
1024
1279
196
4608
4863
210
8192
8447
224
1280
1535
197
4864
5119
211
8448
8703
225
1536
1792
2048
1791
2047
2303
198
199
200
5120
5376
5632
5375
5631
5887
212
213
214
8704
8960
9216
8959
9215
9471
226
227
228
2304
2559
201
5888
6143
215
9472
9727
229
2560
2815
202
6144
6399
216
9728
9983
230
2816
3071
203
6400
6655
217
9984
10239
231
3072
3327
204
6656
6911
218
3328
3583
205
6912
7167
219
CV29 MUST be set to 34 OR 38 to enable the Extended (4-digit) Address!
Desired Address: 6492
Range: 6400 to 6655
CV17: 217
CV18: 6492 - 6400 = 92
Desired Address: 9267
Range: 9216 to 9271
CV17: 228
CV18: 9267 – 9216 = 51
More Important CVs
CV 29 Decoder Configuration
*Sets the type of address used – 2 or 4 digit
*Sets the Speed Step mode (14/27 or 28/128)
*Sets the use of speed tables
*Sets operation of decoder equipped loco on DC
*Sets locomotive directionality in case of miswire
Yet More Important CVs
CV 19 – Advanced Consist (MU) Address
*Range of consist addresses 1 – 127
(NCE PowerCab 112-127 only)
*Used to combine two or more locomotives into lash-ups
*Can be programmed manually or through DCC system
“Consist” menu(s)
*Takes priority over regular locomotive address unless set
to 0
*Add 128 to consist address for locos running in reverse
Last of the Important CVs
Decoder Reset CV
*Most decoders CV 8 to 8 resets the decoder
*Some decoders use other methods
*SoundTraxx uses CV 30 to 2 (CV 8 to 8 also)
(Must interrupt track power – 16 headlight flashes confirms reset)
*Lenz uses register 8 to 33
Decoder Function Outputs
•Functions are outputs for controlling bulbs, LEDs, relays, etc.
•Color coding for easy wiring – NMRA standard
Pin 1 – orange motor +
Pin 2 – yellow reverse light (F0r)
Pin 3 – green wire (typically not used)
Pin 4 – black left rail track pickup
Pin 8 – red right rail track pickup
Pin 7 – blue + common for lights
Pin 6 – white forward light (F0f)
Pin 5 – grey motor –
•White, Yellow, Green (Purple) are function output wires (-)
•Some decoders have 4, 5, or 6 function outputs for more lights
•Blue wire is ALL lights common (+) and about 12 volts
•1k ohm ¼ watt resistors required in most cases for LEDs
(Some decoders have resistors built-in)
-LED Cathode (-) goes to function output wire
-Each LED should use its own resistor
Function Outputs Continued
•Lighting effects available on some decoders – Gyralite,
MARS light, beacons, strobe lights, firebox flicker, FRED,
dimming, ditchlights, etc.
•Sound decoders use functions to control sound effects –
some sound effects can be tied to lighting effects
(alternate flashing ditchlights when horn is sounded)
•Represented on cabs / throttles by F0 to F12 – most
systems and some decoders follow the newer NMRA
standard 28 function control
Motor Control
PWM – Pulse Width Modulation
•All decoders use PWM to control motor speed and direction
•The motor is switched on and off between zero and full power
•Speed is controlled by varying the ratio of OFF and ON time
•Example half speed is full power 50% of the time
Speed Steps
•Decoder splits minimum and maximum throttle range into
speed steps
•Speed steps are set via the throttle per locomotive
•More speed steps means finer control of the locomotive
•14 and 28 speed steps are NMRA standard
•128 speed steps is also supported
•For a maximum voltage of 14 volts DC, each speed step on
a straight line speed curve will equal:
-14 Speed Steps - 1 volt per Speed Step increment
-28 Speed Steps 0.5 volt per Speed Step increment
-128 Speed Steps 0.11 volts per Speed Step increment
Back EMF Motor Control
•Motors generate electricity when they turn and it can be
measured
•Also called cruise control
•Uses motor back-EMF to sense motor speed
•Helps maintain constant speed up and down grades
•Improves low speed performance and control
High Frequency Drive
•Known as silent drive, Supersonic, HyperDrive
•Increases the frequency of the PWM signal to prevent motor
buzzing
Stall Current
•The amount of current drawn by a motor at full voltage with
armature locked up
•Must be matched to decoder specifications
•Most HO decoders are rated for 1.1A continuous
with up to 2A peak
•A locomotive that draws more current than the decoder
is rated for can turn a decoder into a smoke unit!
High End DCC Systems
All Prices M.S.R.P. as of March 2014
NCE Power Pro
Wireless - $699.95
Wired - $529.95
Lenz Set-100 - $497.50
MRC Prodigy Elite - $549.98
Digitrax Super Chief Xtra
Wireless - $665.00
Wired - $455.00
ESU ECoS 2 - $899.90
Mid Range DCC Systems
All Prices M.S.R.P. as of March 2014
Digitrax Super Empire Builder Xtra
Wireless – $575.00
Wired – $355.00
Bachmann Dynamis
Basic – $175.00
+ Dynamis Pro Box ($500) = $675.00
Lenz Set-90 - $442.50
CVP Easy DCC
Wireless – $529.00
Wired – $429.00
MRC Prodigy Advance2
Wireless – $629.98
Wired – $439.98
Entry Level Systems
All Prices M.S.R.P. as of March 2014
NCE DCC Twin: $159.95
NCE PowerCab: $199.95
Digitrax Zephyr Xtra: $225.00
MRC Prodigy Express2: $224.98
CVP Easy DCC Basic: $279.98
Lenz Set 01: $199.87
Due Dec. 2013
Bachmann E-Z Command: $168.00
Common Myth #1
“DCC allows you to control your whole layout with only two wires
connected to the track”
Yeah, Right!
•Reverse loops & wyes must be wired with a reversing switch or DCC
compatible reversing module.
•Blocks are still needed for signaling
•Power districts are recommended for medium and larger layouts
•Cables are needed for cab buses, electric turnout control, and any
other animation you desire
Common Myth #2
“Stall current is the same as operating current”
Stall current can be three or four times larger
than the operating current and should always be
verified to prevent pre-mature decoder failure.
Common Myth #3
“The NMRA DCC standard is comprehensive and all equipment
works together”
The NMRA standard only defines the signal on the rails. Most
other aspects of a system are left to the manufacturer such as
cab wiring, CV assignments, and so forth. Some interoperability
occurs between manufacturers sharing or copying certain
proprietary specifications.
Basic compatibility between decoders and systems is actually
very good (not perfect) and represents the bulk of a users time
and money investment.
Common Myth #4
“DCC layouts require special track switches”
So called DCC friendly track switches simply have an
insulated frog. You must gap the frog rails just as you would
for an analog DC layout. Track switches with non-insulated
frogs can be used just as readily.
Common Myth #5
“The track doesn’t need to be kept clean because it
is always at full voltage”
DCC requires extremely clean track as does an analog DC
layout. Clean track is essential for reliable operation. If the
locomotive can’t pick up the DCC signal or power to operate,
you’ll have stuttering locomotives leading to frustration.
DCC User Advantages
•More fun
•More features
•Runs your locomotives directly, not your track
•More prototypical operation
•New technology continuously being developed appeals
to new modelers
•Easier to run multiple trains
Helpful DCC Books and Links
Practical Guide to Digital Command Control - Larry Puckett
Carstens Publishing – ISBN 978-1590730126 M.S.R.P. $24.95
DCC Made Easy: Digital Command Control for your Model Railroad - Lionel Strang
Kalmbach Publishing – ISBN 978-0890246160 Out of Print
Price Varies
Basic DCC Wiring for Your Model Railroad – Mike Polsgrove
Kalmbach Publishing – ISBN 978-0890247938 M.S.R.P. $15.95
The DCC Guide – Don Fiehmann
Kalmbach Publishing – ISBN 978-0890246 M.S.R.P. $19.95
Helpful DCC Books and Links continued
DCC Projects & Applications – Mike Polsgrove
Kalmbach Publishing – ISBN 978-0890246450 M.S.R.P. $19.95
DCC Projects & Applications Vol. 2 – Mike Polsgrove with David Popp
Kalmbach Publishing – ISBN 978-0890247747 M.S.R.P. $19.95
http://www.ncedcc.com
http://www.digitrax.com
http://www.lenzusa.com
http://www.modelrec.com http://www.esu.eu/en/start/ http://www.soundtraxx.com
http://www.cvpusa.com
http://www.bachmanntrains.com
http://www.qsisolutions.com
http://www.tonystrains.com
http://www.carstensbookstore.com http://www.kalmbachbookstore.com
http://www.litchfieldstation.com
http://www.ulrichmodels.com
http://www.jmri.org
QUESTIONS
Thanks for Coming – Enjoy the show!