Page 6 Function-Decoders MX681, MX685, MX686, MX687, MX688
3.3
Decoder-ID, Load -Code, Decoder-Type and SW-Version
CV
Denomination
Range
Default Description
#250,
#251,
#252,
#253
Decoder-ID
also contains a code (in
CV #250) that identifies
the decoder type
Read only
-
The decoder ID (serial number) is automatically entered
during production: The first Byte (CV #250) denotes the
decoder type; the three other Bytes contain the serial
number.
The decoder ID is primarily used for automatic address
recognition when an engine is placed on the layout
track (future function) as well as in conjunction with the
“load code” for “coded” sound projects (see CV #260 -
263).
#8
Manufacturer ID
and
HARD RESET
or
ACTIVATION
of special CV sets
Read only
For pseudo
programming
see “Descrip-
tion” column
on the right.
145
( = ZIMO)
Reading out this CV always result in “145”
(”10010001”), the number issued for ZIMO by the
NMRA.
This CV is also used to reset the decoder by Pseudo-
Programming.
Pseudo-Programming means that the entered value is not
really stored, but rather used to start a defined action.
CV #8 = “8”
HARD RESET
(NMRA standard);
all CVs reset to the last active
CV set,
or the default
values listed in this CV table if no such set was active.
CV #8 = “9”
HARD RESET for old LGB-operation
(14 speed steps, pulse chain commands).
Further options: see chapter “CV Sets”!
#7
Manufacturer Version
No.
(SW-Version)
Also see CV #65 for
Sub-Version Number
and
special procedures for pro-
gramming with “Lokmaus-2”
and other “low level” sys-
tems
Read only
Pseudo-
programm.
see explana-
tion to the right
-
This CV holds the version number of the firmware cur-
rently in the decoder.
With the help of “Pseudo-programming” it also helps to
program decoders with DCC systems of limited range:
Ones digit = 1: Subsequent programming value + 100
= 2: ... + 200
Tens digit = 1: Subsequent CV number
+ 100
= 2: … + 200
etc.
= 9: … + 900
Hundreds digit = 0: Revaluation applies only once
= 1: Revaluation applies until power-off
#65
SW-
Sub-Version Number
Also see CV #7 for
Version Number
Read only
-
This CV indicates a possible sub-version number of the
main version noted in CV #7.
The entire SW version number is thus composed of
CV #7 and #65 (i.e.: 28.15).
3.4 The (first) vehicle address
Decoders are usually programmed at delivery to
address 3
(
CV #1 = 3
),
for the DCC as well as the
MM (Märklin Motorola) format. All aspects of operation are possible with this address but it is recom-
mended to change to a different address as soon as possible.
The DCC address range goes up to 10239 and therefore exceeds the range of a single CV. Ad-
dresses higher than 127 are stored in CV #17 and #18. Bit 5 in CV #29 is used to select between the
short address in CV #1 and the long address in CVs #17/18.
Most digital systems (with the possible exception of very old or simple products) calculate the value
for the CV’s involved automatically and also set Bit 5 in CV #29 to the proper value when writing the
address, so that the user does not have to deal with the necessary coding.
CV
Denomination
Range
Default Description
#1
Primary (short) Address
DCC:
1 - 127
MM:
1 - 80
3
The “short” (1-byte) loco address (DCC, MM).
In the case of DCC:
The address in CV #1 is only valid if CV #29, Bit 5 = 0.
If CV #29 Bit 5 = 1, the long address in CV #17 + #18 is
used.
#17
+
#18
Extended (long)
address
128
-
10239
0
The long DCC address applies to addresses >127.
It is only active if CV #29 Bit 5 = 1.
#29
Configuration Data #1
0 - 63
14 =
0000 1110
with
Bit 5 = 0
(for short
address)
Bit 0 - Train direction:
0 = normal, 1 = reversed
Bit 1 - Number of speed steps:
0 = 14, 1 = 28
Bit 2 - DC operation (analog): *)
0 = disabled 1 = enabled
Bit 3 -
RailCom („bidirectional communication“)
0 = deactivated 1 = activated
Bit 4 - Individual speed table:
0 = off, CV #2, 5 and 6 are active.
1 = on, according to CV s #67
– 94
Bit 5 - Decoder address selection:
0 = short address as per CV #1
1 = long address as per CV #17+18
Decoder-
controlled consisting (a.k.a. “Advanced consisting”)
Combined operation of two or more locomotives (consisting) can be organized by
- the DCC system (common practice with ZIMO systems, without changing any CVs) or
- by the following CVs, which can be programmed manually or managed by the DCC system (often the
case with American systems).
This chapter covers only the latter; the decoder controlled consisting!
