Functional description of PRxx1 series controllers Rev.H.doc
2016-10-28
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Fig. 5 Network System without CPR32-SE
2.2 Communication
2.2.1 RS485 communication bus
Communication with PRxx1 controllers is based on RS485 interface and devices in RS485 network
must have unique address (ID=00-99). A single communication bus may accommodate up to 32
access controllers (complete Network) and one optional CPR32-SE unit. The RACS4 system
communication topology of Network is fairly flexible i.e. tree structures as well as star topologies
are allowed, however loop topology is forbidden. Regular signal cables can be used and unshielded
twisted-pair wire is recommended. Terminating resistors at either end of the communication bus
are not required.
Maximum cable lengths in the RACS4 system are as follows:
Between any controller and CPR32-SE: 1200 m
Between any controller and interface device: 1200 m
Between CPR32-SE and interface device: 1200 m
Note: All devices connected to RS485 bus must share the same ground potential, and this condition
is clearly satisfied if all devices are supplied from the same power supply unit. If more than one
power supply unit is used, then negative DC terminals of each power supply unit need to be
connected with each other by means of additional wire (could be standard signal wire). If such
connection is not feasible for any reasons, negative DC output of each power supply unit should be
earthed separately, however, the difference of earth potential across all units cannot /-2V.
DO NOT short circuit positive terminals of power supply.
The structure incorporating RS485 communication bus, access controllers and optional CPR32-SE
unit is called an Access Control Network or simply a Network (or Subsystem). Each Network in the
RACS4 system must be connected to PC via a separate communication port. It can be the standard
COM Port, Virtual COM Port (VCP) or Ethernet port. In case of VCP, users can use interface device
(Roger), which emulates COM port, e.g. RUD-1 or UT-2USB. In case of Ethernet port, UT-4DR is
recommended
Each type of PRxx1 controller can manage single door in one-way or two-way mode. Presently,
RACS4 permits integration of up to 250 Networks (Subsystems), each including up to 32 controllers.
PC with PR Master software communicates with each Network by means of separate communication
port, which means that it is possible to integrate Networks connected to PC by means of following
interfaces: RS232, USB, Ethernet and Wi-Fi, thus creating one access control system.
Note: All mentioned communication interfaces can be used not only for controller programming but
also for the management of entire access control system, depending on applied scenario (see 2.1
Available scenarios of operation). In case of on-site programming, we recommend RUD-1 interface
device that provides built-in 12VDC output which can be used to supply programmed device.
2.2.2 Controller address
Each controller connected to RACS4 system communication bus (RS485) must have its own address
in range of 00-99. Default address is ID=00 and can be modified either remotely using PR Master
software (Roger) or manually (see 3.1 Memory Reset – Setting MASTER identifier and ID address of
the controller and 3.3 Installer Programming Mode) or by means of jumpers (only PR411DR).
Moreover, it is possible to assign a so called “FixedID” to the controller. This option is particularly
useful if there is a risk that someone will accidently change controller address resulting in disruption
of the whole system. The fixed address can be set, changed or cleared only by means of RogerISP
software during firmware upgrade procedure.
Besides mentioned methods of addressing, the PR411DR controller offers the option to set address
by means of programming jumpers. The whole range of possible address is 0-127. If controller
