CPR network controllers are optional elements of RACS system and they enable extension of the system by additional functions. The scope of such additional functions depends on types of installed CPR and access controllers. The list of functions is quite extensive and it is necessary to get acquainted with technical documentation of the product, however key properties of each CPR type‑ are listed for comparison in the table below. Installation of CPR is particularly beneficial in case of access control system based on PRxx1 series controllers, because they can neither buffer events nor control time based access rights.