ahmed.elshab replied to Powered By Dodge V8's topic in Allen BradleyHi All, I have the same issue, but wit RSLinx 2.59.22, which is the latest revision. Using ControlLogix 5300, firmware revision 20. RSLinx driver is Ethernet Device ETH-1 1756. Scenario: The system has 10 AB PLCs connected to different level 1 rockell switches. RSLogix is installed on redundant Servers 2008 R2. Once any one PLC or more go offline, it will crash the the remaining OPC communication with remaining PLCs. So losing any PLC will cause carshing of the remaining OPC! Any suggestion?