Installation guide

8 en | Materials Planning Access Control by Example
| 1.0 | 2009.10 Introductory Guide Bosch Security Systems
and key fobs which usually carry no printed personal information.
2.2.3 Wiring for non-reader components
Depending on its manufacturer and model, each of these electrical components will require a
certain number of wires to control its operation. Typical values for number of wires per
component can be found in the table below.
If you know the total number of wires a door (with all its electrical components) requires, and
if you have access to the site during the building phase, then you can influence the kinds of
cable which are laid to the doors.
Cables differ both in the number and the thickness of their wires (also known as “cores”). For
distances under 25m, as in our example; a wire thickness of AWG18 or 1mm² will be
sufficient. For longer distances and stronger currents correspondingly thicker wires will be
required. The AMC2 tolerates a maximum 2V drop from AMC to the devices. Voltage drop is
calculated by electricians according to standard formulae.
It is advisable to use a spreadsheet to track the sum and thickness of wires required per door.
2.3 Middle tier: Access Controllers
An access controller is an electronic device which handles input and output signals from and
to the peripheral components (readers, door controllers, REX units, magnetic contacts etc). It
is an interface through which the access control software communicates with these
components, but the controller is able to handle some signal events on its own if it
temporarily loses its connection to the software.
Examples are the Access Modular Controller AMC2 and the Access Easy Controller from
Bosch Security Systems. The Access Easy Controller is controller hardware with a resident
access control application. The AMC2 is software/host/reader neutral and provides variants to
handle either RS-485 or Wiegand readers.
Electrical component Typical
number of
wires
Notes/explanation
Door opener 2 Power only
Magnetic contact 2 2 wires for power, but often extra wires for
tamper detection
REX with push button 2 E.g. so that the receptionist can open the main
entrance from her desk.
REX with motion
detector
6 Highly variable depending on manufacturer: 2
wires for power, 2 to the magnetic contacts
Burglar alarm 4 (not used in this example)
Emergency exit 4 (not used in this example)
NOTICE! Remember, although RS-485 readers can be wired together in a bus topology, other
components are wired to the controller directly, i.e. in a star topology.
Although some RS-485 readers do provide limited connections for REX and/or magnetic
contacts, we do not use that specialized functionality in this example.