Overview

An M580 network can transmit data from distributed equipment. This is accomplished by using equipment that is configured to implement the following network design principles:

• CPU: CPU with Ethernet I/O scanner service on the local rack

• BMENOS0300 network option switch module

• Implementation of Defined Architectures: An M580 network supports the addition of DIO data traffic only in specific network designs, including one of these:

  • a main ring joined by a BMENOS0300 network option switch module to a DIO cloud

  • a main ring with one or more RIO drops

  These designs provide a limited number and type of junctions between network segments and a limited hop count from any device to the CPU.

• QoS Traffic Prioritization: DIO packets are assigned the lower priority. They wait in a queue until a device finishes transmitting all RIO data packets. This limits RIO jitter to 128 µs, which represents the time required to complete the transmission of one DIO packet that has already begun.

• DIO data is not delivered in real-time: DIO packets wait in a queue until all RIO packets are transmitted. DIO data transmissions use the network bandwidth that remains after RIO data has been delivered.