Function-Decoders MX681, MX685, MX686, MX687, MX688 Page 5
3
Addressing and Programming
ZIMO decoders can be programmed in
-
“Service Mode”
(on the
programming track
) for assigning a new address or reading and writing
CV content but also in
-
“Operational Mode”
(a.k.a. “Programming on the main” or “PoM”), which is done on the main
track; programming CVs “on the main” is always possible in operational mode. However, an
acknowledgement of successful programming steps or reading out of CVs is only possible with a
DCC system capable of
RailCom
.
3.1
Programming in
“Service mode” (on programming track
)
Before programming is actually possible, the decoder must be unlocked with
CV #144 = 0
or
= 128 (
the latter allows programming but prevents decoder updating).
This is normally the case but in many sound projects the programming lock is activated to prevent ac-
cidental changes. Therefore, it is useful to check that CV, especially when programming attempts
have already failed.
The acknowledgments of successful programming steps on the programming track as well as CV
read-outs are accomplished by power pulses, which the decoder generates by briefly engaging the
motor and/or headlights. If the motor and/or headlights do not draw enough power
or don’t draw pow-
er at all (i.e. they are not connected), acknowledgments for successful programming or CV read-outs
are not possible.
To make acknowledgments possible in such cases activate CV #112 bit 1, which enables the decoder
to use an alternate acknowledgment by sending high frequency pulses from the motor end stage.
Whether this method is successful though depends on the DCC system used.
CV
Denomination
Range
Default Description
#144
Programming and
Update Lock
Note: The programming
lock has no effect on
CV #144, which is there-
fore always accessible
for unlocking.
0,
64,
128,
192
0
= 0: programming and update lock not active
Bit 6 = 1: programming the decoder in „Service
Mode“ is blocked as a protection against
unwanted reprogramming.
Note: Programming in
“Operational Mode” is not
locked because any such programming only
applies to the active loco address and
reprogramming the wrong locomotive is
therefore not possible.
Bit 7 = 1: Software updates via MXDECUP, MX31ZL or
other means are locked.
#112
Special ZIMO
configuration bits
0 - 255
2
Bit 1 = 0: Normal acknowledgment in
“Service Mode”;
by activating motor and headlight outputs.
= 1: High frequency pulses instead of normal
acknowledgments from motor and headlights.
Bit 2 = 0: Loco number ID is OFF
etc.
3.2
Programmi
ng in “Operational mode” (a.k.a. on-the-main, “PoM“)
According to the current NMRA DCC standards it is only possible to program and read CVs on the
main track, but not to assign new vehicle addresses. However, certain DCC systems (among them
ZIMO with the system generation MX10/MX32 and later) will allow addresses to be modified on the
main track with the help of bidirectional communication.
All ZIMO decoders are equipped with bidirectional communication (
“RailCom”
) and can therefore
(with a corresponding DCC system such as ZIMO MX31ZL and all devices of the new MX10/MX32
generation) read, program and acknowledge successful CV programming steps in operational mode
(on the main track). This requires RailCom to be activated, which is the case if the following CVs are
set as:
CV #29, Bit 3 = 1
AND
CV #28 = 3
This is usually the default setting, except in certain sound projects or OEM CV sets, in which they need
to be set first.
CV
Denomination
Range
Default Description
#28
Bi-Directional
Communication
Configuration
0 - 3
3
Bit 0 - RailCom Channel 1 (Broadcast)
0 = OFF
1 = ON
Bit 1 - RailCom Channel 2 (Data)
0 = OFF
1 = ON
#29
Configuration Data #1
0 - 63
14 =
0000
1
110
Bit 3 = 1
(“RailCom” is
activated)
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:
0 = primary address as per CV #1
1 = ext. address as per CV #17+18
*
Broadcast
: Decoder sends information without being requested
Data
: Decoder sends information only upon request.
