13
GB
Z21 Connecting the Z21 Detector to the Track System:
Switching tracks or dry reed contact
The simplest form of the message feedback is the use of dry reed contacts or switching tracks that are
earth-switched. A generation of an occupied message is only possible if a 3.3k ohm resistor (not included)
is activated between the detector input and the switching element. Should the resistance be too low, the
track voltages is burdened unnecessarily or the module or resistance respectively are damaged.
Current sensor
With this method, the feedback devices measure the current that is owing through the track section. This
results in each of the current consumers generating an occupied message for this section.
2-conductor track
For the power supply, connect the inputs P and N to the corresponding booster outputs and connect the 8
feedback terminals to the corresponding feedback sections.
Note: The feedback sections are
to be separated from the system
from both sides.
Please also ensure that the se-
paration consistently takes place
on the correct voltage side.
Short circuiting could otherwise
occur when the separation
points are crossed.
3,3k Ohm
Note: The ROCO articles 42518, 42605,
61117 and 61193 contain electronic
components inside the connector for
protecting the reed-contact, which can
lead to unwanted occupancy messages
at the detector input. In such a case,
increase the setting for the occupancy
threshold in the detector to 4 to 5 mA,
see also section Con guration using the
Z21 Maintenance Tool.