Fahim shah

dear all  i have  2 NOE cards (network TCP/IP card) on a modicon quantum hotstandby system, one NOE install at primary CPU and one on secondary CPU. both NOE cards communicate with InTouch through same switch. the problem is that i can't write data to the plc whenever both NOE card are on the network. when i remove the standby controller from the network i can write data to the plc. the switchover of hotstandby is tested and working fine. can anyone tell what i am missing here. thanks i advance

both plc are not in  standby mode,  it is confirmed only one at time is in primary mode. suppose i have controller A in pri mode i can only read & write data to plc only if my standby is disconnected from network. if i disconnected  the pri controller from network and connect the secondary controller to the network in this case now i can only read data from plc can't write to it which is good. but if i connect both pri and hotstandby controller to the network now i can only read. i have configure both NOE cards ip address to the 19.168.1.101 and i am writing to  same ip address.  i am using 140 NOE 211 card and quantum 140 CPU 534. i think my NOE didn't support Automatic IP swap over on Hotsatandy