ZIMO MX638 Series Instruction Manual page 55

Non-Sound Decoder MX600 - MX638 and Sound Decoder MX640 - MX659
Connecting an electric (un)coupler (System "Krois"):
In order to prevent damage to the delicate core of an uncoupler from continuous power, appropriate
adjustments can be made with special CV's for one or several function outputs.
First, write the value "48" to the special effect CV that is assigned to the same output an uncoupler is
connected to (e.g. CV #127 for output #1, CV #128 for output #2 etc.)
Next define a limit for the uncoupler's activation time in CV #115 (see CV-table):
With the "Krois uncouplers", it is recommended to use a value of "60", "70" or "80" for CV #115; this
means that the pull-in voltage (full track voltage) is limited to 2, 3 or 4 seconds. A reduced "hold" volt-
age is not required for Krois, that's why the ones digit is left at 0. Other uncouplers may need a re-
duced hold voltage though, like the ones from ROCO for example.
Regarding the "automated train disengagement" and/or "automatic coupler unloading" see CV #116 in
the chapter "Addressing and programming", section "Configuration of Electric Uncouplers".
MX622R, MX623R, MX630R... with NMRA 8-pin interface (NEM 652):
The "R" designated decoders come with an 8-pin plug mounted to
the end of its wires, which fits in to the socket of a DCC ready loco.
Remove the dummy connector from the socket and plug the de-
coder in its place, that's all.
All the necessary connections to power, motor and headlights are
established with this interface. Other outputs have to be hard wired.
MX621F, MX623F, MX630F...
The "F" designated decoders come with a 6-pin plug mounted to the
end of its wires, which fits into the socket of a DCC ready loco.
The brightness of the headlight is reduced since the blue wire
(common supply) is not part of this interface. The light bulbs get
their power directly from the power pick up.
The blue wire is still available at the decoder and can be used if re-
quired, but when used on aforementioned bulbs that get power directly from the track (usually through
the frame) they must first be isolated from the power source!
MX621N, MX622N - plugs directly into the 6-pin interface (NEM 651):
Many N, HOe, HOm as well as some HO engines have this socket installed with the required mini-
mum space of 14 x 9 mm to accept the decoder.
ATTENTION:
Plug the decoder into the socket with the pins down and the microprocessor on top (visible)!
L front (white)
L rear ( yellow )
Motor (gray)
Motor (orange)
Power (blue)
Rail (black)
Rail (red)
with NMRA 6-pin interface (NEM 651):
Front headlight ( white )
Rear headlight (yellow)
Motor (orange)
Motor (gray)
Common positive (blue)
Rail (black)
Rail (red)
6-pin
Loco socket
Decoder MX620N
Loco board
MX631D, MX632D, MX632VD, MX632WD, MX640D, MX642D, MX644D
MX631C, MX632C, MX640C, MX642C. MX644C - with 21-pin interface:
These decoders have a 21-pin female plug on the circuit board (no wires), which allows the decoder
to be plugged directly in to the 21-pin male receptacle of locomotives equipped with such interfaces.
There are actually 22 pins present but one of those pins (#11, top right) serves as a key to prevent
wrong installations. The 21-pin interface is standardized by the NMRA-DCC PR 9.1.1., just like the 6
and 8-pin interfaces (see schematic below left).
Vcc Index
12 11
Aux 3 Speaker
13
10
Aux 2 Speaker
14 9
Aux 1 F0, front
15 8
Common pos. F0, rear
16 7
Motor 3 17 6 Train Bus Data
Motor 2 Train Bus Clock
18 5
Motor 1 Aux 4
19 4
Ground 20 Hall 2
3
Left rail 21 2 Hall 3
Right rail Hall 1
22 1
Since the original definition of the 21-
pin interface was designed for a cer-
tain motor configuration (C-Sinus),
some of the pins are not used for the
intended purpose (Hall effect sensor,
motor 3) with "normal" applications
and are being used for other func-
tions instead.
The "C-Type" decoders MX631C, MX632C,
MX640C, MX642C differ from the "D-type" by
the function outputs FO3 and FO4: logic level
outputs for "C", normal outputs for "D".
"C-Type" for Märklin. Trix and LS models.
Page 55
M X 6 3 2 D , C To p S id e
V D W D
a nd M X 6 3 2 , M X 6 3 2
+ 5 V Index pin
Function output FO3
n.a.
Function output FO2 n.a.
Function output FO1 Front headlight
Common positive
Rear headlight
Low voltage (...V, W) SUSI Data (or FO6, Servo 2)
Motor connection 1
SUSI Clock (or FO5, Servo 1)
Motor connection 2 Function output FO4
Ground
Function output FO5
Left rail
Function output FO6
Right rail
n.a. for capacitor negative (not ground),
M X6 4 0 D To p Sid e
5 V, 200 mA, for small servo
(= 21-pin plug side!)
+ 5 V, 200 mA max. Index pin
Function output FO3 Speaker
Function output FO2 Speaker
Function output FO1 Front headlight
Common positive Rear headlight
n.a. SUSI Data
Motor connection left SUSI Clock
Motor connection right Function output FO4
Ground n.a.
Left rail n.a.
Right rail Switch input 1
Therefore, depending on decoder configura-
tion, there are slightly different pin configura-
tions on the 21-pin socket connector. These
additional outputs can only be used if the ve-
hicle is specially adapted to it. For example,
the function outputs FO4 - FO6 and the low
voltage supply of the MX632D are also
available at other solder pads on the decod-
er; see the connection diagrams in the chap-
ter "Technical Information".
Decoders with the 21-pin plug can be in-
stalled in two ways; the decoder board be-
low the connector is perforated so that the
decoder can be plugged in from the top or
bottom end, depending on the locomotive.
The index pin 11 prevents a wrong installa-
tion by not allowing the decoder to be
pushed all the way down.
on special request only