connecting 1761 NET ENI to ML1500

Using 2707-NC9 but instead of 8 pin DIN on one end, I replaced it with DB9 connector. will the ML1500 still communicate with NET ENI?

Also, What does it mean that it only has 6 max connections? if I connect ML1500 to NET ENI and NET ENI to 1783 ETAP to form a ring network,will the ControlLogix from another network be able to monitor the ML1500? the ML1500 are independent of each other.

Regarding the cable, yes, it should work as long as you get the pinout correct.

The 1783 ETAP seems to me to be a 3 port managed switch with some ring topology management features built-in. In other words, it is just another switch as seen by the NET-ENI. Outside of setting up proper IP addresses and subnet masks, there should be no problem with the Control Logix communicating with the ML1500.

The connection limit on the NET-ENI is allocated to 2 dedicated incoming connections, 2 dedicated outgoing connections and 2 that can be used as either in or out. So, if you have a message instruction in one of the ML1500 sending to another ML1500, the sending unit will use up one of those outgoing connections and the receiving unit will use one of the incoming connections. A PC running an OPC server reading/writing values from the PLC will also use these same connections. Most people here will recommend against using the NET-ENI and suggest the Digi One IAP instead. It seems that the NET-ENI will not always release these connections and stop communicating when the connection limit is reached, requiring a power cycle to recover. That is at least the theory.

Shawn

Shawn, Thank you for the reply. I will see to it that no other MSG will happen among the ML1500 and only the CLx which is the master will access them. The ring network is only for redundancy