Overview

An M580 system provides deterministic services to remote I/O drops and to individual RIO modules. Distributed equipment does not have the same level of determinism, but it can participate on an RIO network without disrupting the determinism of the RIO modules.

In order to achieve this determinism, the RIO network follows a set of simple rules that are explained in this chapter.

  • One CPU with Ethernet I/O scanner service is installed in the local rack.

  • One BM•CRA312•0 eX80 EIO adapter module is installed in each RIO drop.

  • Follow the rules regarding the maximum number of devices allowed (e.g., 32 devices, in the main ring, including the local rack, and 31 RIO drops in the RIO network), the types of cables you select, and respect Control Expert messages during programming and diagnostic checks.

  • Optional elements include a maximum of six communication modules, including a maximum of three BMENOC0301/BMENOC0311 modules and BMENOS0300 network option switch modules, and only one BMENOC0321 control network module.

Each M580 CPU supports only one Ethernet RIO network. This section helps you select the RIO network that allows improved response time for remote equipment operations.

In addition, preferred DIO network topologies are discussed in detail so that you can construct a device network that works harmoniously with the RIO network's deterministic operation.

NOTE: The architectures described in this document have been tested and validated in various scenarios. If you intend to use architectures different than the ones described in this document, test and validate them thoroughly before implementing.
NOTE: To use a dual-ring switch (DRS) to connect distributed equipment to the M580 network, refer to the M580 System Planning Guide for Complex Topologies.