5
connecting to contacts, which are switching to ground, e. g. circuit tracks, reed switches, push button switches (see fig. 5). With
the feedback decoder item 5217 the digital control system is able to recognize and analyze proceedings running at the layout and
to react appropriately.
2.1 Connecting the decoder to the digital system
The decoder is connected directly to the 6-pin s88 socket at the rear of the Memory or the Interface (Märklin or Arnold), of the
Intellibox (Uhlenbrock), or the Twin-Center (Fleischmann) via the included special cable, with the power of the digital system
switched off. Be absolutely sure the special plug is positioned correctly (see fig. 1). It must be inserted in all devices so that the
ribbon cable runs downward.
Up to 31 feedback decoders item 5217 or 62 feedback decoders with track occupancy detectors item 5233 can be connected
to the Märklin Interface, the Fleischmann Twin-Center, or the Uhlenbrock Intellibox. This means that one feedback decoder item
5217 (16 inputs) can be replaced by two item 5233’s with 8 inputs each. The total number of decoder inputs can be up to 496.
The feedback decoder with track occupancy detector item 5233 and the feedback decoder item 5217 (or s88) can be combined
with each other in any sequence.
The decoders are automatically numbered in sequence from 1 to 31 by the central control unit or the interface. Two consecutive
item 5233 decoders each get the same address (see fig 2).
Please note:
Always switch off the power when connecting the special cable! The arrow printed on the feedback decoder must
point in the direction of the digital control center! Please note that parts of the decoder are very sensitive to static electricity! Plug
the special cable carefully onto the contact pin (the pins bend easily)!
2.2 Special information for the Intellibox and the Twin-Center:
The connection is made at the socket marked „s88“. In the basic settings menu, you must enter how many feedback decoders are
connected under the point „s88 settings“.
2.3 Special information for the memory:
Up to three items 5217’s can be connected to a Memory from Märklin. These will be addressed automatically by Memory when you
switch on the system. The inputs of the feedback decoders are divided up into two groups (1 – 8 and 9 – 16). By operating input
“1”, a route programmed before can be activated (signals and turnouts switch to a predefined position). When the train arrives
at its destination, the first route has to be released by input “9”. The first input belongs to the ninth, the second to the tenth one,
etc. With three feedback decoders you are able to program 24 routes. A route can contain up to 20 commands altogether. The
keygroup A1 – A8 corresponds to the first decoder input, keygroup B1 – B8 to the second and C1 – C8 to the last one (see fig.
4). It is possible to turn on and off the external trigger of switch-function by the Memory keys “extern” and “off”. So the system can
be toggled between manual and automatic running. By adjusting the code switch on the backside of the Memory, it is possible to
block the call of a new route.
3. Connection
3.1 Connecting to (Märklin) third-rail track:
The various possibilities to connect the item 5217 to Märklin third rail tracks are shown in fig. 5. You can make contact track sec-
tions with single side insulations of the grounding rail. In addition you can use Märklin switching tracks because they also switch
against ground if they are activated by the cars’ center slider.
3.2 Connecting to two-rail / two-conductor systems:
Connecting the item 5217 directly to two-rail / two-conductor track unfortunately is not possible. For this you would have to put an
occupancy detector in front of every input of the item 5217.
Instead we recommend to use the feedback decoder item 5233 (please refer to section “introduction”).
3.3 Connecting to switching contacts:
Independent of your track system you can connect potential free switching contacts (like reed contacts which are activated by
magnets underneath the vehicles) to the inputs of the item 5217 decoder. Then you have to connect the second cable from the
switching contact to one of the two grounding sockets located at the right side of the item 5217 feedback decoder. To avoid jam-
mings please always use the grounding sockets of the same decoder to which the contact is connected.
4. Technical data
Data format
s88 - format
Inputs 1 – 16
Polarity react on ground impulses ( )
Dimensions
10.9 x 5.4 x 2.35 cm
Subject to change without prior notice. No liability for mistakes and
printing errors.
You will find the latest version of the manual on the Viessmann
website using the item number.
Do not dispose of this product through (unsorted)
domestic waste, supply it to recycling instead.
