ZIMO MX681 User manual

Function-Decoders MX681, MX685, MX686, MX687, MX688 Page 1
INSTRUCTION MANUAL
MX681N
MX681
MX685P16
MX685
2
MX686
MX686D
(Design since 2013)
MX689
MINIATURE - FUNCTION - DECODER
MX681, MX681R, MX681N
FUNCTION - DECODER
MX685, MX685R, MX685P16
FUNCTION - DECODER with energy storage circuitry
MX686, MX686D MX688N18
FUNCTION - DECODER with energy storage circuitry and low-voltage output
MX687V, MX687W, MX687WD
FUNCTION - DECODER with NEXT-18 interface
MX688N18
1Overview.................................................................................................................2
2Technical Information...............................................................................................3
3Adressing and Programming....................................................................................5
3.1 Programming in “Service mode” (on programming track) .........................................................5
3.2 Programming in “Operations mode” (a.k.a. on-the-main, “PoM“) .............................................5
3.3 Decoder-ID, Load -Code, Decoder-Type and SW-Version.......................................................6
3.4 The (first) vehicle address .........................................................................................................6
3.5 The second address in a function decoder ...............................................................................7
3.6 Analog operation........................................................................................................................7
3.7 “Virtual” motor control and momentum ......................................................................................8
3.8 The NMRA-DCC function mapping .........................................................................................10
3.9 “Unilateral Light Suppression” .................................................................................................11
3.10 The “Swiss Mapping” (SW version 32 and higher)...............................................................11
3.11 Dimming, Low beam and Direction Bits...................................................................................12
3.12 The Flasher Effect....................................................................................................................13
3.13 F1- Pulse Chains (only for old LGB products).........................................................................13
3.14 Special Effects for Function Outputs (US and other lighting effects…) ..................................14
3.15 Configuration of Electric Uncouplers .......................................................................................15
3.16 SUSI-Interface and Logic-Level Output...................................................................................15
3.17 Servo Configuration.................................................................................................................15
4Feedback - “Bidirectional communication”.............................................................16
5Operating with Märklin MOTOROLA Systems........................................................ 17
6ZIMO Decoder - Software Update.......................................................................... 17
NOTE:
ZIMO decoders contain anEEPROM which stores software that determines its characteristics and functions. The software version can be read out form CV #7 and
#65. The current version may not yet be capable of all the functionsmentioned in this manual. As with other computer programs, it is also not possible for the
manufacturer to thoroughly test this software with all the numerous possible applications. Installing new software versions later can add new functions or correct
recognized errors. SW updates can be done by the end user for all ZIMO decoders since production date October 2004, see chapter “Software Update”! Software
updates are available at no charge if performed by the end user (except for the purchase of a programming module); Updates and/or upgradesperformed by ZIMO
are not considered a warranty repair and are at the expense of the customer. The warranty covers hardware damage exclusively, provided such damage is not
caused by the user or other equipment connected to the decoder. For update versions, see www.zimo.at.
EDITION
First edition --- 2011 08 15
2012 08 15
2015 01 25
2015 02 05
MX688N18 supplement --- 2015 11 16
Swiss Mapping --- 2016 06 23
2018 05 25
2018 07 11

Page 2 Function-Decoders MX681, MX685, MX686, MX687, MX688
1 Overview
Function decoders are locomotive decoders for non-motorized vehicles and are therefore not
equipped with a motor end stage but do offer special features for use in cars usually belonging to a
“block train” pulled or pushed by a locomotive.
The hardware of the MX685 function decoder is based on the loco decoder MX630 (board and hard-
ware is almost identical), the MX686 (on the MX631 until 2012) from 2013 onwards on the MX634
and the miniature function decoder MX681 on the miniature decoder MX621. The dimensions and
most of their features are therefore identical to the decoder they are based on.
A distinctive feature of all ZIMO function decoders is the programmable SECOND ADDRESS (CVs
#64 to #68), which can be used as an alternative address for the coach containing the function de-
coder and is commonly set to the same address as the loco pulling the train. If all coaches of a train
are equipped with such a decoder using the same (second) address, they can all be controlled simul-
taneously with a single key stroke (i.e. the interior light of all coaches are turned ON/OFF with a func-
tion key of the loco address, if that is the second address). With this, the simplest form of a virtual
“train bus” becomes reality, which will certainly play a major role in future digital train technology.
12 x 6.5 x 2 mm 0.7 A -4 Fu-Outputs DCC and DC-Analog (but not MOTOROLA)
MX681
Family
Miniature-Function-Decoder,with reduced ZIMO features; the software does
not contain: MM (Motorola), Servos, SUSI, ZIMO spec. Function mapping.
MX681 plug configurations:
MX681
MX681N
(MX681R)
(MX681F)
7 wires (120mm long) for power pick-up, 4 function outputs. Solder pads are
available for further outputs.
MX681 with 6-pin plug as per NEM651 and NMRA RP 9.1.1., mounted to the
circuit board.
(Versions with 8-pin plug as per NEM652 on 70mm wires
or 6-pin plug on 70mm wires; special order only).
20 x 11 x 3.5 mm 1.0 A - 8 Fu-Outputs -2 Servos - SUSI
MX685
Family
Function-Decoder, compact design for universal applications.
MX685 plug configurations:
MX685
MX685P16
(MX685R)
(MX685F)
7 wires (120mm long) for power pick-up, 4 function outputs. Solder pads are
available for further outputs and for 2 servos or SUSI.
MX685 with 16-pin PluX connector mounted on decoder board.
(Versions with 8-pin plug as per NEM652 on 70mm wires
or 6-pin plug on 70mm wires; special order only).
20.5 x 15.5 x 4mm 1.2A - 8 Fu-Outputs - 2 Servos - SUSI
MX686
Family
High performance Function-Decoder with built-in energy storage circuitry.
MX686 plug configurations:
MX686
MX686D
7 wires (120mm long) for power pick-up, 4 function outputs. Solder pads are
available for further outputs as well as for servo or SUSI.
MX686 with 21-pin “MTC” plug mounted directly on decoder board.
20.5 x 15.5 x 4 mm 1.2 A - 8 Fu-Outputs - 2 Servos - SUSI
MX687
Family
High performance Function-Decoder with built-in energy storage circuitry
and low-voltage output (1.5 V or 5 V).
MX687 plug configurations:
MX687V
MX687W
MX687WD
10 wires (120mm long) for power pick-up, 4 function outputs. Solder pads are
available for further outputs as well as for servo or SUSI. Low voltage output of
1.5V.
Same as MX687V but with 5 V low-voltage output.
Same as MX687V but with 5 V low-voltage output and
21-pin “MTC“ plug mounted on circuit board.
15 x 9.5 x 2.8 mm 0.7 A - 8 Fu-Outputs - 2 Servos - SUSI
MX688
Function-Decoder,only available with Next-18 interface

Function-Decoders MX681, MX685, MX686, MX687, MX688 Page 3
2 Technical Information
Allowable track voltage **) ................................................................................... min. 10 V
MX681 ........................................................................................................… max. 35 V
MX685, MX686, MX687, MX688, MX689…….. DCC and DC-Analog operation . max. 35 V
MX685, MX686, MX687, MX688, MX689 AC-Analog operation .. max. power pulse 50 V
Maximum continuous motor current MX681, MX681R, MX681N ......................................... 0.8 A
MX685, MX685R, MX685P16 ................................. 1.0 A
MX688N18 .................................................................. 0.7 A
MX686, MX686D, MX687V / W / WD, MX689 ............ 1.2 A
Operating temperature ............................................................................................ - 20 to 100 oC
Dimensions (L x W x H) ............ MX681, MX681R, MX681N…………………….. 12 x 8.5 x 2 mm
MX685, MX685R, MX685P16 ………………. 20 x 11 x 3.5 mm
MX686, MX686D……………………………. 20.5 x 15.5 x 4 mm
MX688N18……………………………………... 15 x 9.5 x 2.8 mm
MX687V, MX687W, MX687WD ……...….... 28 x 15.5 x 4 mm
MX689, MX689P22………………………………..30 x 15 x 4 mm
*) The short circuit protection is carried out for the total current of all outputs. Use the “soft start” op-
tion (i.e. CV #125 = 52) to prevent cold-start problems of light bulbs (in-rush current interpreted as a
short circuit, which leads to the output being turned off!
Software - Update:
ZIMO decoders can be updated by the user, provided that one of the following update devices is at
hand: ZIMO decoder update-module MXULF (since 2011), system-cab MX31ZL or command sta-
tion MX10. The updating process is carried out via a USB stick (MXULF, MX31ZL / MX10) or a PC
with Windows operating system and the program ZIMO Firmware Flasher (within the ZIMO Sound
Programmer ZSP).
The same hardware together with the program ZSP is also used to load sound projects into the de-
coder.
There is no need to remove the decoder or to open up the locomotive. Just set the locomotive on
a track section connected to the update module and start the update with the computer or other
equipment mentioned above.

Page 4 Function-Decoders MX681, MX685, MX686, MX687, MX688

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 Programming 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 1110
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.