Page 50 Non-Sound Decoder MX618 - MX634 and Sound Decoder MX640 - MX648
also determines the proper time the compressor is started af-
ter coming to a stop!
#316
Random generator
Z1
Maximum interval
0 - 255
=
0 - 255 sec
60
CV #316 defines the maximum time interval between two
consecutive pulses of the random generator Z1 (that is most
often the start of the compressor after coming to a stop); the
actually occurring pulses between the values in CV #315 and
#316 are equally distributed.
#317
Random generator
Z1
Playback length
0 - 255
=
0 - 255 sec
5
The sound sample assigned to the random generator Z1
(most often the compressor) is played back for the number of
times defined in CV #317.
= 0: Sample plays once (in the defined duration)
#318
#319
#320
As above but for
sound generator Z2
0 - 255
0 - 255
0 - 255
20
80
5
By default, Z2 is assigned for coal shoveling at stand-still.
#321
#320
#323
As above but for
sound generator Z3
0 - 255
0 - 255
0 - 255
30
90
3
By default, Z3 is assigned for the injector at stand-still.
#324
#325
#326
As above but for
sound generator Z4
0 - 255
0 - 255
0 - 255
As delivered, this random generator is not assigned to any
sound.
#327
#328
#329
As above but for
sound generator Z5
0 - 255
0 - 255
0 - 255
As delivered, this random generator is not assigned to any
sound.
#330
#331
#332
As above but for
sound generator Z6
0 - 255
0 - 255
0 - 255
As delivered, this random generator is not assigned to any
sound.
#333
#334
#335
As above but for
sound generator Z7
0 - 255
0 - 255
0 - 255
As delivered, this random generator is not assigned to any
sound.
#336
#337
#338
As above but for
sound generator Z8
0 - 255
0 - 255
0 - 255
As delivered, this random generator is not assigned to any
sound.
#341
Switch input 1
Playback duration
0 - 255
=
0 - 255 sec
0
The sound sample allocated to switch input 1 is played back
for the duration defined with this CV.
= 0: Play back once (duration as recorded)
#342
Switch input 2
Playback duration
0 - 255
=
0 - 255 sec
0
The sound sample allocated to switch input 2 is played back
for the duration defined with this CV.
= 0: Play back once (duration as recorded)
#343
Switch input 3
(if not used for the
cam sensor)
Playback time
0 - 255
=
0 - 255 sec
0
The sound sample allocated to switch input 3 is played back
for the duration defined with this CV.
= 0: Play back once (duration as recorded)
6
Installation and Wiring
General information:
There has to be enough
free space inside the engine
so that the decoder can be mounted without
exerting mechanical stress. Pay particular attention that no pressure is applied to the decoder when
the loco housing is being reinstalled
and the wires can’t get caught by movable parts.
All direct connections that are present in the original wiring configuration between the power pick-ups
(wheels and wipers) and the motor
must be isolated;
otherwise the motor end stage may get dam-
aged at power-up.
The same goes for the
headlights and other additional accessories,
which must be completely iso-
lated.
Do noise suppression components on a locomotive motor have
a negative effect on motor regulation?
Yes, sometimes . . .
Explanation: Motors of model railroad locomotives are often equipped with choke coils and capaci-
tors, which are supposed to suppress or filter out electric noise caused by sparks arcing across the
motor’s brushes (causing poor TV reception etc.).
Such components impair the motor regulation. Compared to others, ZIMO decoders manage quite
well and there is hardly a difference in performance with or without those components in place. How-
ever, in recent years larger choke coils are being installed in many locomotives than was the case
earlier
– and these can noticeably compromise drivability.
The potentially “harmful” choke coils are often recognizable by their shape, as they look like a resistor
with color bands (in contrast to a wire wound ferrite bar). That doesn’t mean though that these choke
coils have a negative effect in all cases.
Lessons learned and accompanying measures…
ROCO, BRAWA, HORNBY
– so far present no problems, no action necessary.
FLEISCHMANN H0 with “Round motors” – choke coils are no problem; capacitors should be removed
if necessary, especially the ones between frame and motor (may destroy the decoder if left in place)!
Newer Bühler motors
– no problems so far.
TRIX H0
– choke coil between track and decoder plug should be removed!
MINITRIX, FLEISCHMANN PICCOLO
– very inconsistent; removing of capacitors is often advanta-
geous; choke coils on the other hand presented no problems so far.
Indications of a harmful effect of such components, besides a general unsatisfactory motor control
(jerking…), are:
- weak BEMF compensation: as confirmation, set the decoder for testing purposes to low frequency
–
CV #9 = 200
– and see whether the control compensation becomes stronger. If that’s the case, the
choke coils are most likely to blame.
- if a difference in compensation is noticeable between 20 kHz and 40 kHz (selectable in CV #112, Bit
5), it is very possible that the choke coils or capacitors are the cause.
Remedy
: Bypass choke coils
(or replace with wire strap)
!
Remove capacitors! Capacitors are less
likely to interfere with motor regulations.
