Non-Sound Decoder MX600 - MX634 and Sound Decoder MX640 - MX658 Page 53
M X 6 3 2 D , C To p S id e
a nd M X 6 3 2
, M X 6 3 2
V D
W D
+ 5 V
Function output FO3
Function output FO2
Function output FO1
Common positive
Low voltage (...V, W)
Motor connection 1
Motor connection 2
Ground
Left rail
Right rail
Index pin
n.a.
n.a.
Front headlight
Rear headlight
SUSI Data (or FO6, Servo 2)
SUSI Clock (or FO5, Servo 1)
Function output FO4
Function output FO5
Function output FO6
n.a.
for capacitor negative (not ground),
on special request only
M X 6 4 0 D To p S id e
+ 5 V, 200 mA max.
Function output FO3
Function output FO2
Function output FO1
Common positive
n.a.
Motor connection left
Motor connection right
Ground
Left rail
Right rail
(= 21-pin plug side!)
Index pin
Speaker
Speaker
Front headlight
Rear headlight
SUSI Data
SUSI Clock
Function output FO4
n.a.
n.a.
Switch input 1
5 V, 200 mA, for small servo
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).
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, motor 3) with
“normal” applications and are being
used for other functions instead.
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
vehicle is specially adapted to it. For exam-
ple, 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.
MX623P12, MX630P16, MX633P22, MX645P16 and MX645
P22…
- Decoder with PluX-Connector:
In contrast to the 21-pin interface (see above), the PluX connection has the male connector mounted
on the decoder and the female on the loco board. “PluX” is available with 8, 12, 16 and 22 pin con-
nectors and also use one of the pins for indexing.
The PluX system is defined by the NMRA 9.1.1 and the NEM, including the maximum dimensions for
standardized decoders.
The MX630P16 comes with a 16-pin male plug (15 usable pins, 1 index
pin) and can be plugged into engines with 16-pin sockets but also in
engines with 22-pin sockets (see drawing at left: brown area = 16-pin).
In 8-pin (yellow) and 12-pin equipped locomotives it depends on the
available space whether the 16-pin version can be used.
The MX630P, which is not a sound decoder, uses the two pins original-
ly defined for speaker outputs for the additional outputs FO3 and FO4
instead. This will not damage speakers that may be installed in the lo-
comotive and connected to those pins
The MX632P12 (which is narrower than the MX630!) has the 12-pin
“PluX” connector. It does not have the upper 4 connections as the
MX630 and therefore does not have SUSI or GROUND connections on
the plug.
The "
C-Type
" decoders MX631C, MX632C,
MX640C, MX642C differ from the "
D-type
" by
the function outputs FO3 and FO4: logic level
output
s for “C”, normal outputs for “D”.
"C-Type" for Märklin. Trix and LS-models.
