Good afternoon, dear specialists. Recently, only without preparation, I began to set up communication between the scada and the PLC. The problem is that RSLINX LITE (v3.90.01 CPR 9 SR9) sees both PLCs on the network, but one of them gives a problem with reading data, or rather, the data monitor does not load at all (or shows a red cross (which means there is no physical connection to the PLC)). But it responds perfectly = 1ms. Nearby is an old PC with an old RSLINX LITE (v2.41.00) that perfectly reads data from both PLCs. What is the problem? why doesn't the more recent program read the data? There is an even older PC on Windows XP on the Intouch scad, via OPC the "SMC" application also reads data without problems New PC: Old PC: still the third ancient PC: Windows 10 Windows 7 Windows XP RSLINX LITE v3.90 RSLINX LITE v 2.41 SMC (intouch) Status Not working Status Working Status Workinп It was also connected via the "Ethernet" and "Ethernet / IP" drivers. I directly connected a new PC to the PLC and set up only one connection, still the result is negative. I would be grateful for any help! If I apologize for my English, I did it through a translator.