Introduction

Each adapter module has a single IP address for its Ethernet ports. Therefore, the address conflict detection algorithm (duplicate IP checking) is performed based on the status (link up, link down) of the ports.

Link Down

These conditions apply when links are lost:

Link Status

Description

A transition has occurred from 1 connected link to all links down.

When no module ports are connected to a cable (all links are down), all services are reset. For example, I/O connections, Modbus connections, and explicit EtherNet/IP connections close, but low-level network services (like RSTP or switches) are not affected. The updated Net Status LED indicates the status.

There is 1 link down and at least 1 connected link.

There is no impact on services that are running in the module.

Link Up

These conditions apply when links are added:

Link Status

Description

A transition has occurred from no connected links to 1 connected link.

A duplicate IP check is performed:

  • no duplicate: All services start.

  • duplicate: I/O services stop. The BM•CRA312•0 adapter module gets new configuration and downloads the IP configuration again. The system goes to default IP and the I/O modules are set to the fallback mode.

A transition has occurred from at least 1 connected link to an additional connected link.

A duplicate IP check is performed:

  • no duplicate: All services continue.

  • duplicate: All services stop.

NOTE: The updated Net Status LED indicates the status.