2500-OPC is an OPC and Communications Server enabling Ethernet communications between Windows-based PC applications and the CTI 2500 Series® PLC system.  2500-OPC replaces 2572-OPC and works with the Ethernet communications ports on 2500-Cxxx Processors and 2572 / 2572-A / 2572-B / 2500C-2572-B / 2500P-ECC1 / 2500C-ECC1 / 505-CP2572 Ethernet Adapter Modules.  IMPORTANT NOTE: 2572-OPC IS NOW PURCHASED DIRECTLY FROM KEPWARE.   Purchase from Kepware web site