ZIMO MX638 Series Instruction Manual page 45

Non-Sound Decoder MX600 - MX638 and Sound Decoder MX640 - MX659
INC-
CV Denomination Range
step
LEAD
- CV
Total volume 0 - 255 5
#266
Chuff sound
frequency with
"virtual cam sensor"
#267 0 - 255 1
also see CV #354 in
this table
(chuff frequency at
speed step 1)
Switching to real
cam sensor
and
0 – 63
trigger count for chuff
#268 rate and 1
and Bits 6 & 7
Special function for
"Simple articulated"
steam engines
Accentuated
LEAD
- CV lead-chuff
0 - 255 10
#269
PROJECT
not functional yet:
Longer chuff length
#270
0 - 255 10
at very low speeds
De-
Description
fault
See chapter
5.4 "Basic settings independent of powertrain"
64
CV #267 is only active if CV #268 = 0:
Chuff beats follow the "virtual cam sensor"; an ac-
tual cam sensor is not needed in this case.
The default setting "70" results in about 4, 6 or 8
chuffs per wheel revolution, depending on the
chuff set selected; because it also depends in
large part on the motor and gearbox used, an in-
70
dividual adjustment is necessary in most cases in
order to achieve the exact chuff frequency. This is
the purpose for CV #267:
The lower the value the higher the chuff frequency
and vice versa. The setting should be performed
at a low speed (around speed step 10), but not at
the lowest speed step 1.
= 0: "Virtual" cam sensor is active (to be adjusted
with CV #267, see above).
= 1: real cam sensor is active (connected to
switch input 2 of the MX640, see chapter 6);
each negative spike results in a chuff beat.
= 2, 3, 4 ... real cam sensor, several triggers in
sequence (2, 3, 4 ...) result in one chuff beat.
= 128 (Bit 7=1 with "virtual" cam sensor): second
driver is a bit slower; only meaningful if a
second sound sample is available in the
0
sound project.
= 192 (Bit 6 and 7 = 1): When no separate sound
sample is available for the second driver, the
same sample is played back for the second
driver albeit a bit slower.
Bit 7 = 1 (with real cam sensor, see above for val-
ues):
Cam sensor for driver 1 on IN3 (as usual),
Cam sensor for driver 2 on IN2 (only possible
if decoder has 2 inputs).
A typical sound signature of a passing steam en-
gine is that one chuff out of a group of 4 or 6
0 chuffs is louder in volume than the rest; this effect
is already part of the chuff set but can be further
amplified with the help of CV #269.
PROJECT (not yet implemented):
The chuff sounds of a real engine are extended
?
when driving at very low speeds due to the me-
chanical valve control. This effect can be more or
less accentuated with CV #270.
INC-
CV Denomination Range
step
0 – 255
Overlapping effect at
(useful
high speed
#271 1
up to @
30)
Blow-off duration
0 - 255
LEAD
- CV
10
=
also see CV #312
#272
0 - 25 sec
(blow-off key)
Start-up delay
0 - 255
during blow-off
#273 1
=
0 - 25 sec
0 - 255
Blow-off schedule
#274 start-up whistle 10
=
schedule
0 - 25 sec
Page 45
De-
Description
fault
The individual steam chuffs of a real engine over-
lap each other at high speed. Because the fre-
quency of the chuffs increases but won't shorten
to the same extend they will eventually blend in to
a weakly modulated swoosh.
16
This is not always desired in model railroading
because it doesn't sound that attractive, hence CV
#271, with which an adjustment is possible to
have the chuff beats accentuated at high speed or
rather fade away.
Opening the cylinder valves on a prototype steam
engine for the purpose of water drainage is entire-
ly up to the engineer. An automated draining at
start-up is more suitable in model railroading; CV
#272 defines how long after start-up the blow-off
sound should play.
50
Value in CV #272 = time in tenths of a second!
=
Note: If the blow-off sound is also allocated to a
5 sec
function key (as delivered on F4, see CV #312),
the automated blow-off sound can be shortened
or extended with the relevant function key. Auto-
mated blow-off and function key blow-off are inevi-
tably the same (as per selection/allocation).
= 0: no blow-off sound playback
Opening the cylinder valves and with it the related
blow-off sound on a real steam engine starts most
often before the engine even starts to move.
This can be imitated with CV #273 by automatical-
ly delaying the start of the locomotive.
This effect is cancelled when a shunting function
with momentum deactivation is being activated
(see allocation of F3 or F4 in CV #124!)
0
= 0: no delayed start
= 1: Special setting for blow-off via speed
regulator; no start-up delay, but setting the
speed to the lowest speed step causes the
blow-off sound to be played without powering
the motor (only with 128 speed steps).
= 2: Start-up delay in tenths of a second,
Recommendation: no values > 20 (> 2 sec)
Constant opening and closing of the cylinder
valves in real shunting operations, that often re-
quires many short trips with associated idle times,
is usually omitted. CV #274 causes the blow-off
sound to be suppressed if the engine wasn't
30
standing still for the time defined here.
Value in CV #274 = time in tenth of a second!
The same stop-time is also used for the start-up
whistle!