User manual

The s88 feedback bus of digital central units and interfaces
can mostly supply a maximum load of up to 0,5 Amp. If the
maximum quantity of 62 feedback modules RM-GB-8-N are
connected, the bus has to supply 62 x 0,003A = 0,186A.
If you want to extend your model railway layout with RM-GB-8-
N feedback modules you can easily combine those with our
feedback modules RM-DEC-88(-Opto) and RM-88-N(-Opto)
or s88 feedback modules of other manufacturers.
The address of the feedback modules is related to the
sequence of the connection to the digital central unit or to
the interface. The feedback module which is directly
connected to the central unit will get always the address 1.
Further details are available within the operation instructions
of your digital central unit or the interface.
The RM-GB-8-N contains two 6-poles pin bars for the s88-
standard connection and two RJ-45 sockets for a bus
connection in accordance to
s88-N
.
At the RM-GB-8-N are the pin bars and sockets marked with
OUT and IN.
OUT is the connection in direction of the digital central
unit or interface. IN shall be connected to the next following
feedback module within the s88 bus line.
Digital central units and interfaces contain always a s88-
input for a s88-standard connection.
We supply an interference protected twisted s88-bus-cable
with original s88-bus plugs for the s88-standard
connection.
The plugs of the s88-bus-cable are correct assembled on
the 6-poles pin bar of the RM-GB-8-N when the position of
the white single wire corresponds to the white marking on
the pc-board next to the pin bar. The cable shall lead directly
away from the feedback module. Additionally attend to the
correct position of plug to prevent any offset to the 6-poles
pin bar.
For a secure s88-bus connection in accordance to
s88-N
we
offer an interference protected blue patch cable with RJ-45
plugs.
Attention: Digital central units with PC-network connection
(e.g. Central Station 1 and 2 and ECoS) contain as well a RJ-
45 socket. The RJ-45 network socket shall never be
connected to the RM-GB-8-N! The RM-GB-8-N shall be
operated with no other supply voltage than +5V. This supply
voltage will be automatically available from your digital central
unit or from your HSI-88 (-USB) via the s88 feedback bus.
Connecting track sections:
Below draft clarifies how to connect the feedback module
RM-GB-8-N to a track.
RM-GB-8-N
7654321 8
From further
feedback modules
Digital current from
command station
or booster
IN1 IN2
Von weiteren
Rückmeldemodulen
Digitalstrom von
Digitalzentraler
oder Booster
s88-N
OUT IN
s88-N
Richtung
Digitalzentrale
Normalgleis
Überwachte Gleisbereiche
Standard track
Monitored areas
Direktion to
command station
Digital current will be supplied to the RM-GB-8-N via input IN1
and IN2. IN1 provides current to the output 1 to 4 and IN2
provides current to the output 5 to 8. The two inputs IN1 and
IN2 are electrical separated.
Therefore will it be possible for example to supply IN1 from the
digital command station (control unit) and IN2 from a booster.
With reason to have a correct feedback report is it required to
supply digital current to both inputs (IN1 and IN2).
By using the control unit or a booster on IN1 or IN2 connect
the digital current for the supply of the continuous rail to
the clamp with the continuous white line.
Output clamps 1 to 8 shall be connected to those isolated
tracks, which shall be monitored. As indicated in the draft it is
sufficient to isolate one rail. The clamp with the dotted line
shall be connected to the rail track section to be monitored.
Detailed sample connections for various application can be
downloaded from our web-site (www.ldt-infocenter.com) within
the section "Downloads".
To avoid short circuits when locomotives are crossing the
transitions of each monitored track, always the same
connecting sequence of the tracks has to be strictly followed.
In case of a short circuit when crossing the transition (control
unit will switch to EMERGENCY STOP) please check the
connections and eventually change the cables of the monitored
track at the respective OUTPUT clamps.
Anti-interference capacitors can lead to an erroneous
occupied detection of the track and should therefore not be
used within the monitored track.
If you apply electrical resistant coating to the axles of your
trains you should measure the resistance value with a
Multimeter afterwards.
A resistance between 5 and 10 KOhm will guarantee a safe
monitoring by the occupied track detection of the feedback
module RM-GB-8-N.
Customary used resistance axles with a resistance value of
18 KOhm will just be monitored, provided that the rails are
very clean and the railway coaches have a sufficient contact
to the rails. In such case it will be recommended, to fit two
resistance axles to the coach to receive a total resistance
value of about 9 KOhm. This will assure a save monitoring
even when the rails are not perfect clean.
Accessory:
For easy assembly of the RM-GB-8-N-F below your model rail
road layout base plate we offer a set of assembly material
under the order identification: MON-SET. Under LDT-02 you
can purchase a low priced durable suitable case.
Trouble shooting:
What to do if something is not working as described above?
If you have purchased the RM-GB-8-N module as a kit, please
carefully check all parts and all soldered joints.
Important: Both inputs (IN1 and IN2) have to be connected to
a digital current.
Possibly test the single monitoring function of the modules first
before connecting it to the tracks.
To do this you can use a resistor (couple of hundred Ohm) or a
small model lamp to simulate the occupied situation on each
output clip.
Without resistor or incandescent lamp the detection of the
input should be indicated as “free”, with a resistor or
incandescent lamp your digital control unit or PC should show
an “occupied” situation. Made in Europe by
Littfinski DatenTechnik (LDT)
Kleiner Ring 9
D-25492 Heist/Germany
Phone: [phone] / 977 381
Fax: [phone] / 977 382
Internet: http://www.ldt-infocenter.com
Subject to technical changes and errors.  07/2015 by LDT
Märklin, and Motorola are registered trademarks.