LDT Littfinski Daten Technik RM-88-N-F Operation Instruction

Littfinski DatenTechnik (LDT)

Operating Instruction

16-fold Feedback Module

for the s88-feedback bus

from the Digital-Professional-Series!

RM-88-N-F Part-No.: 310112

>> finished module <<

⇒ with 16 input connections, switching against

ground (e.g. for contact tracks [one isolated rail], switch

tracks or reed-contacts).

⇒ for s88-standard connections and s88-N

(with 6-poles s88-pinbars and RJ-45 sockets).

⇒ suitable for the digital control:

Märklin-Digital~/=, Central Station 1 and 2, Intellibox, TWIN-

This product is not a toy! Not suitable for children under 14 years of age! The kit
contains small parts, which should be kept away from children under 3 years of
age! Improper use will imply danger of injuring due to sharp edges and tips!
Please store this instruction carefully.

CENTER, HSI-88(-USB), EasyControl, ECoS, DiCoStation.

CE Part-No.:

24 80 32

s88-N

Introduction / Safety Information:

You have purchased the feedback module RM-88-N for your
digital model railway.

The RM-88-N is a high quality product, which is supplied within
the Digital-Professional-Series of Littfinski DatenTechnik
(LDT).

We are wishing you having a good time using this product.
The finished modules come with 24 month warranty.

• Please read the following instructions carefully. Warranty will
expire due to damages caused by disregarding the operating
instructions. LDT will also not be liable for any consequential
damage caused by improper use or installation.

• Attention: Please switch-off your digital control unit and
unplug all transformers from AC-current before starting
any installation.

General functions:

The feedback module RM-88-N contains 16 inputs, which will
switch against ground. The module is compatible to the Märklin
feedback module s88.

Connecting the RM-88-N to command
stations or interfaces:

Up to 31 feedback modules RM-88-N can evaluate the reports
of a Märklin INTERFACE, Central Station 1 and 2, Intellibox,

TWIN-CENTER, EasyControl, ECoS, HSI-88-(USB) and
DiCoStation.

On each Märklin Memory can be up to 3 feedback modules
RM-88-N connected.

All feedback modules will receive the operating current from
the s88-feedback bus.

If you want to extend your layout with RM-88-N feedback
modules you can combine those with our feedback modules
RM-DEC-88(-Opto), RM-88-N-O, RM-GB-8(-N) respectively
with s88 feedback module of other manufacturers.

The addresses of the feedback modules are related to the
sequence of the connection to the command station
respectively to the interface. The feedback module, which is
directly connected to the central unit, will receive always the

address 1. Further details can be found within the operation
instruction of your command station respectively your
interface.

The feedback module RM-88-N contain two 6-poles pin-bars
for the s88-standard connection and as well two RJ-45

sockets for a bus connection according to
N are pin-bars and sockets marked with OUT and IN.

s88-N

. At the RM-88-

Out indicates the connection in direction to the command
station or interface. IN indicates the connection to the next
following feedback module within the s88-bus line.

Command stations and interfaces are always equipped with

an s88-input for an s88-standard connection.
For the s88-standard connection is an interference
protected twisted s88-bus cable with original s88-bus plugs
available.

The plugs of the s88-bus cable are correct attached onto the

6-poles pin-bar of the RM-88-N if the white single wire
corresponds with the white marking on the pc-board next to
the pin-bar.

The direction of the cable has to be directly away from the
feedback module. Additionally attend to the position of the
plugs on the 6-poles pin-bars. No offset will be acceptable.

For the

patch-cable with RJ-45 plugs.

s88-N

s88-bus connection we offer a screened blue

Attention: Command stations with PC-network connection
(e.g. Central Station 1 and 2 and ECoS) contain as well a RJ­45 socket. It is not acceptable to connect the RM-88-N to
the RJ-45 network sockets.

s88-N

OUT

s88-N

IN

Connection of contacts:

1. Three-conductor rail-system

At the feedback module RM-88-N all contacts can be connected
which are switching against ground (mostly digital wire
“brown”).

Therefore is it possible to switch against the feedback module
connection clamp marked ⊥ or against the connection 0 (brown)
of the rails.

Switch rails, contact rails and reed-contacts can be
connected to the clamps 1 to 16 as shown below.

123

123

4

contact track

Kontaktgleis

Type of contact

Kontaktart

123

4

Schaltgleis

switch track

At section 2 (two-conductor rail system) you can find an
additional possibility to connect reed-contacts. The second
connection of the reed-contact will not be soldered to the
connection 0 of the track but connected to the ground clamp ⊥
at the feedback module.

All shown above connections are conform exactly to the known
wiring of the Märklin feedback module s88.

Further sample connections can be found at the Internet on our
Web Site (www.ldt-infocenter.com) at the section “Downloads”
and “Sample Connections”.

Beside the single sample connections we recommend the file
“RM-88_Info” within the section “Downloads”.

To avoid interferences and wrong occupancy reports by
feedback module, which are switching against ground, is it
recommended not to install the connection cable to the 16
inputs together with digital current carrying cables (e.g. common
cable channel).

If the connection cables to the contacts are very long and
installed very narrow (e.g. within one cable with several wires) it
can even come to some signal transfer between two wires.
Although only one section is actually occupied several sections
can be reported to be occupied.

But also the particularly simple track occupied report from
contact rails (one isolated rail) can initiate problems because
the isolated rail runs inevitable parallel to the digital current
carrying middle conductor.
As longer a contact track as sooner interferences are possible.
As a result the input can be switched temporarily to be occupied
although no train is on the respective track section.

The described problems can be solved by using interference
suppression diodes or decoupling diodes before the single
inputs. A sample wiring can be found on our Web Site at the
section “Sample Connections”.
Alternative is it possible to use the feedback module RM-88-N-

O that is less sensitive against interferences due to opto­coupling inputs.

4

reed contact

Reedkontakt

2. Two-conductor rail-system:

If you use reed contacts or other potential-free contacts for
feedback signals on your layout you can install the wiring to the
feedback module RM-88-N as shown at the below circuit.

Reedkontakt
reed contact

4
3
2
1

Even the shortest switch impulses will be transferred by the
feedback module RM-88-N because they will be stored via the
s88-feedback bus until the digital control unit or the interface
will request this information.

Feedback module from our Digital-Professional-Series are
easy to use on your digital model railroad, as they are 100%
compatible with the s88 feedback bus.

Accessories:

For safe installation of the feedback module below your model
layout we offer an installation set under the order code MON-
SET and for the assembled kits a sturdy exact matching case
(order code: LDT-01).

Further products from our Digital-Professional­Series:

RM-88-N-O
16-fold feedback module with integrated opto coupling­inputs for the s88-feedback bus.

RM-GB-8
8-fold feedback module with integrated occupancy
detectors for the s88 feedback bus.

S-DEC-4
4-fold turnout decoder for 4 magnet accessories with free

programmable decoder addresses and possible external power
supply.

M-DEC
4-fold decoder for motor driven turnouts. For motors up to

1A. With free programmable decoder addresses. Drives can be
connected directly with the decoder output.

LS-DEC
Light signal decoder for up to 4 LED train signals. Signal signs

will be originally dimmed up and down and directly positioned
via the decoder address.

Littfinski DatenTechnik (LDT)

D-25492 Heist/Germany

Phone: [phone] / 977 381

Fax: [phone] / 977 382

Internet: http://www.ldt-infocenter.com

Subject to technical changes and errors.  02/2013 by LDT

Märklin and Arnold are registered trademarks.

Made in Europe by

Kleiner Ring 9