Functional description of PRxx1 series controllers Rev.H.doc
2016-10-28
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address is set in range of 0-99 then it cannot be changed neither by means of PR Master nor
manually. It can be modified only if jumper address is set above 99. For details regarding various
address settings refer to the relevant Installation Guide.
Note: The fixed address (FixedID) has always the highest priority – if it is set then it can be
modified only using RogerISP software during firmware upgrade procedure.
2.2.3 RACS Clock and Data Interface
Besides the RS485 communication bus, PRxx1 controllers feature also the so-called RACS Clock &
Data interface (alternatively called: Internal Bus). This interface is used for communication with
external PRT series readers and/or XM-2 I/O extension module. RACS Clock&Data interface
incorporates two lines: CLK and DTA. The following devices can be connected to the internal bus:
Primary access reader (Terminal ID0, address ID=0)
Secondary access reader (Terminal ID1, address ID=1) (only PR411DR)
XM-2 input/output extension module (address ID=5)
Fig. 6 RACS Clock&Data interface
Note: If there are no devices connected to CLK and DTA lines then it is possible to configure these
lines as standard transistor type outputs, capable to sink up to 150mA/15VDC.
For CLK/DTA lines any type of signal cable can be used. There is no need to use either twisted or
shielded cables. The maximum cable length between controller and external reader and/or XM-2
extension module is limited to 150m. Similarly as in case of RS485 bus, all devices connected to
CLK/DTA line should have common negative terminals. Such condition is usually satisfied because
devices connected to CLK/DTA line are usually directly supplied from controller. Otherwise negative
terminal of each reader must be connected to respective controller GND or COM terminal.
