ZIMO MX695 Instruction Manual Download Page 25

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Large-scale Decoder & Sound Decoder MX695, MX696, MX697, MX699 Page 25

Designation

Range

Default Description

33.25

rapidly to full speed.

Bit 5 = 1: Overlapping of chuff beats

#309

Brake key

From SW-Version

33.25

0 - 28

The key defined here starts a braking the engine ac-
cording to the brake time defined in CV #349 (the
normal

– higher – deceleration time in CV #4 is being

ignored.

#349

Deceleration time for

brake key

From SW-Version

33.25

0 - 255

For the desired effect to work, the normal deceleration
time in CV #4 must be set to a very high value (i.e.
50…250) and the deceleration time in CV #349 to a
rather low value (i.e. 5…20).
Moving the speed regulator to 0 with these settings
simulates a coasting effect while pressing the brake
key brings to engine to a rapid stop.

#146

Compensation for

gear backlash

during direction chang-

es in order to reduce

start-up jolts

0 - 255

= 1 to 255: the motor spins at minimum rpm (accord-
ing to CV #2) for a specific time and only starts to ac-
celerate after this time has elapsed. This CV will only
be executed after a direction change.

How much time is required to overcome the backlash
depends on various circumstances and can only be
determined by trial and error.
Typical values are:

= 100: the motor turns about 1 revolution or a
maximum of 1 second at the minimum speed.

= 50: about ½ a turn or max. ½ second.
= 200: about 2 turns or max. 2 seconds.

Important: The minimum speed must be set correctly,
so that the motor actually turns at the speed step de-
fined as the lowest step in CV #2. Also, CV #146 is
only useful if the load regulation is set to maximum or
at least close to it (i.e. CV #58 = 200

– 255).

Note

The actual

acceleration and deceleration

rates for HLU brake sections

(ZIMO signal controlled speed influence) are also determined by CV #49 and #50.

Momentum

– explained in more detail:

The momentum (acceleration and deceleration rates) according to CV #3 and #4 refers to the 255
internal steps which are spaced equally from 0 to full speed. The selected speed table, whether 3-
step or 28-step, does not influence the momentum behavior.

The momentum CANNOT be changed by bending the speed curve in the speed tables, but is very
much pos

sible with the “exponential acceleration/deceleration” in CV #121 and #122.

5.8

Special Operating Mode “km/h – speed regulation

“

The km/h (Kilometer per hour) speed regulation is an alternative method of driving with proto-
typical speeds in all operating situ

ations: the cab’s speed steps (1 to 126 in the so-called “128

speed step mode”) will be directly interpreted as km/h.
However, ZIMO decoders do not simply convert the speed steps to a km/h scale but rather en-
sure that the desired speed is held, by recalculating the already traveled distance and auto-
matically make the necessary adjustments.

A CALIBRATION RUN must be performed with each engine:

First, we need to determine the calibration distance: a section of track that measures 100 scale
meters (plus the necessary acceleration and deceleration distances before and after), of
course without inclines, tight radii and other obstacles; for example, for HO (1:87) 115cm; for
G-scale (1:22.5) 4.5m. Mark the start and end points of the calibration section.

Step 1. Set the engine on the track, with the proper travel direction selected, about 1 to 2 me-

ters (3

– 6 ft) before the start marker and the function F0 (headlights)

turned off.

Ac-

celeration times (in CV #3 of the decoder as well as settings in the cab) should be set
to 0 or a very small value.

Step 2. Start the calibration mode by programming

CV #135 = 1

(operations mode program-

ming). This is a pseudo-programming because the value of 1 does not replace the val-
ue already stored in CV #135.

Step 3. Set the speed regulator to a

medium speed

position (1/3 to ½ of full speed); the loco

accelerates towards the start marker.

Step 4. As the engine passes the

start marker,

turn on

the function

(headlights);

turn F0

off

again when passing by the

end marker.

This ends the calibration run and the loco

may be stopped.

Step 5.

CV #136 can now be read out for checking purposes. The calibration “result” stored in
that CV doesn’t mean very much by itself. If however, several calibration runs are per-
formed, the value in CV #136 should approximately be the same every time, even if the
traveling speed was different.

Km/h Speed Regulation in Operation:

CV # 135

controls the selection between “normal” or km/h operation:

CV # 135 = 0:

The engine is controlled in “normal” mode; a possible km/h calibration run per-

formed earlier has no effect but the calibration results remain stored in CV #136.

CV #135 = 10, 20 or 5: each external speed step (1 to 126) becomes
1 km/h, 2 km/h or 0.5 km/h: see CV table below!

The speed regulation in km/h is not just useful for direct throttle control, but also for speed lim-
its through the “signal controlled speed influence” (CV’s 51 – 55). The values entered to those
CV’s are also being interpreted in km/h.

Designation

Range

Default Description

#135

km/h

–

speed regulation

activating, control and

range definition

2 - 20

= 0: km/h

– regulation turned off; the “normal” speed