Page 28 MS-SOUND decoders MS440 to MS990
The “asymmetrical DCC signal” is an alternative method for stopping trains (e.g. at a red signal). A simple
circuit made up of 4 or 5 commercially available diodes is all that is required.
Usually, the stop section contains 3 to 5 silicon diodes in series and one diode in parallel in the opposite di-
rection is the usual arrangement. The differ-
ent voltage drops across the diodes results in
an asymmetry of about 1 to 2 V. The direction
in which the diodes are mounted determines
the polarity of the asymmetry and with it the
driving direction a signal stop is initiated.
The asymmetrical DCC signal stop mode
needs to be activated in the decoder with CV
#27. Usually, bit 0 is set, that is CV #27 = 1.
This results in the same directional control as
the “Gold” decoder from Lenz.
CV
Denomination
Range
Default Description
#27
Position-dependent
Stopping
(“before a red signal”)
or driving slowly
by
“asymmetrical DCC sig-
nal“ (“Lenz ABC“)
All details and settings
are described in chapter
“Stop in front of a red
signal and driving
slowly... “
or “ZIMO HLU
”
Automatic stopping
by DC brake section,
also:
“Märklin brake section”
Only possible, if analog
operation is locked; i.e.
if
CV #12, bits 0 und 4 = 0
0 =
ABC not
active,
HLU
active,
other
brake
sections
not active
Bit 0 and Bit 1 = 0: ABC not activated; no stopping
Bit 0 = 1: Stops are initiated if the voltage in the right
rail (in direction of travel) is higher than in the left rail.
This (CV #27 = 1) is the usual ABC application)
Bit 1 = 1: ABC stops are initiated if the voltage in the left
rail (in direction of travel) is higher than in the right rail.
If bit 0 or bit 1 =1 (only one of the two bits is set):
Stopping is directional, i.e. only in direction of travel to
the signal, travelling in opposite direction has no effect.
Bit 0 and Bit 1 = 1: Stops are independent of direction
of travel. See chapter “stop in front… (Lenz ABC)”
Bit 2 = 0: HLU train protection system (H, UH,…) active
= 1: Effect (halt, limit) of HLU deactivated
Bit 4 - DC braking section, if polarity is reversed
0 = disabled 1 = enabled
Bit 5 - DC braking section, if polarity
is equal to direction of travel
0 = disabled 1 = enabled
Bit 4 and bit 5 = 1 (CV #27 = 48): stopping when
DC voltage (e.g. by a diode) independent
of the polarity (“Märklin brake section”)
#49,
#50
Acceleration,
braking time
0 - 255
0
Effect like HLU, therefore see chapter “ZIMO signal-
controlled speed influence”.
If those CVs are not used, CVs #3 and #4 are valid.
#53
slow speed
0 - 255
70
Internal speed steps for the ABC slow speed
#193
ABC - commuting
with stopping times in
reverse loops
0,
1 - 255
0
= 0: no commuting on ABC basis
= 1 - 255: Stopping period (in sec) in the ABC stopping
(=turnaround) sections at the end of the commuting
distance.
CV
Denomination
Range
Default Description
#194
ABC - commuting
with additional
pit stops
0,
1 - 254,
255
0
Only as commuting if CV #193 = 1 - 255
= 0: Commuting without pit stops (see above)
= 1 - 254: Commuting with pit stops
(terminal loops by ABC slow-speed sections,
pit stops defined by ABC stopping sections)
Stopping period (in sec) in the pit stops
= 255: as above but permanent stop in pit stops
(until stop is cancelled).
CV
Denomination
Range
Default Description
#29
Basic Configuration
0 - 63
14 =
0000 1
1
10
so
Bit 2 = 1
When using DC brake sections, the automatic switch-
over to analog operation must be switched off.
So that settings in CV #27, bits 4 and 5 are effective:
CV #29, Bit 2 = 0
(e.g. CV #29 = 6, instead of the default value 14)
Bit 0 - Directional behavior
Bit 1 - Number of speed steps
Bit 2 - Automatic switching to analog operation
0 = off, 1 = switched on
Bit 3 - RailCom (bi-directional communication)
Bit 5 - Selection of vehicle address (DCC)
#27
Position-dependent
Stopping
(“before a red signal”)
or driving slowly
by
“asymmetrical DCC sig-
nal“ (“Lenz ABC“)
See chapter
“Stop in front of a red
signal and driving
slowly... “
or
“ZIMO HLU”
(see chapter ‘ZIMO “sig-
nal-controlled speed in-
fluence” (HLU)’)
or
DC brake sections
(“Märklin brake section”)
0 =
ABC not
active,
HLU
active,
other
brake
sections
not active
Bit 0 and Bit 1 = 0: ABC not activated; no stopping
Bit 0 = 1: Stops are initiated if the voltage in the right
rail (in direction of travel) is higher than in the left rail.
This (CV #27 = 1) is the usual ABC application)
Bit 1 = 1: ABC stops are initiated if the voltage in the left
rail (in direction of travel) is higher than in the right rail.
If bit 0 or bit 1 =1 (only one of the two bits is set):
Stopping is directional, i.e. only in direction of travel to
the signal, travelling in opposite direction has no effect.
Bit 0 and Bit 1 = 1: Stops are independent of direction
of travel. See chapter “stop in front… (Lenz ABC)”
Bit 2 = 0: HLU train protection system (H, UH,…) active
= 1: Effect (halt, limit) of HLU deactivated
Bit 4 - DC braking section, if polarity is reversed
0 = disabled 1 = enabled
Bit 5 - DC braking section, if polarity
is equal to direction of travel
0 = disabled 1 = enabled
Bit 4 and bit 5 = 1 (CV #27 = 48): stopping when
DC voltage (e.g. by a diode) independent
of the polarity (“Märklin brake section”)
H
alteabschnitt
Fahrspannung
vom Basisgerät (Zentrale)
Silicium-Dioden,
beispielsweise
1N5400x
(3 A - Typen)
Allgemeine Strecke
Fahrtrichtung
Schalter für
Aufhebung des Halts
bei “Signal
auf Fahrt"
Hinweis: 3 Dioden in Serie
ist die Mindestzahl, um bei
ZIMO Decodern zu wirken;
für Fremd-Decoder werden
manchmal 4 oder mehr
Dioden benötigt ! Da durch
die Dioden ein unerwünschter
Spannungsverlust entsteht,
verwendet man die Mindestzahl
je nach eingesetzten Decodern.
rot
