Planning an M580 Hot Standby Topology

Linking Primary and Standby PACs

The BMEH58•040 and BMEH58•040S primary and standby PACs are connected by a Hot Standby link, and may also be connected by an Ethernet link.

NOTE:

Every M580 Hot Standby system design includes a Hot Standby link.
The Ethernet link provides a redundant path on the main ring. Its presence helps prevent the occurrence of two primary PACs. Although the system can function without an Ethernet link connecting the primary and standby PACs, such a system is not optimal.

NOTE: For a description of maximum lengths between (e)X80 RIO drops, refer to the topic Planning the Appropriate Network Topology in the Modicon M580 System Planning Guide for Frequently Used Architectures.

Hot Standby Link Between Primary and Standby PACs

NOTICE

UNINTENDED EQUIPMENT OPERATION

When installing modules with fiber optic transceivers, do the following to help prevent dust and pollution from disrupting light production into the fiber optic cable:

Keep caps on jumpers and transceivers when not in use.
Insert the optical cable into the transceivers carefully, respecting the longitudinal axis of the transceiver.
Do not use force when inserting the cable into the optical transceivers.

Failure to follow these instructions can result in equipment damage.

Each BMEH58•040 and BMEH58•040S CPU is fitted with an SFP socket for an SFP transceiver, which can be either:

An SFP copper wire transceiver with RJ45 connector.
An SFP single mode fiber optic transceiver.

Your choice of connector determines the maximum distance of the Hot Standby physical link.

SFP transceiver name	Media	Maximum Hot Standby Link Length
490 NAC 01 00	CAT 5e copper wire1	100 m (328 ft)
490 NAC 02 01	Single mode fiber optic cable	up to 15 km (9.3 mi)
1. Compatible with Gigabit data transfer rate.

NOTE: BMXNRP020• fiber converter modules cannot be used on the Hot Standby link.

Ethernet Link Between Primary and Standby PACs

The primary and standby BMEH58•040 or BMEH58•040S PACs can also be connected to each other by an Ethernet link. This link is typically part of an Ethernet RIO main ring, to which each Hot Standby CPU is connected.

Each BMEH58•040 and BMEH58•040S CPU includes two RJ45 connectors dedicated for use as a dual port to the main ring.

To create the Ethernet link between the primary and standby PACs, connect one of the dual Ethernet ports on the primary CPU to a dual Ethernet port on the standby CPU. You can do this in one of the following ways:

Directly connect the primary and standby CPUs using CAT-5e copper wire.
Place a BMENOS0300 switch module in each PAC, or place a BMENOC0301/11 communication module in each local rack, then connect the two modules.
Connect each CPU to a BMXNRP0201 fiber converter module, then connect the two BMXNRP0201 modules with single-mode fiber optic cable, as described below:

primary local rack with primary CPU

standby local rack with standby CPU

Ethernet RIO fiber optic link between primary and standby CPUs (part of Ethernet RIO main ring)

Hot Standby fiber optic communication link

(e)X80 EIO drop

Ethernet RIO main ring

BMENOC0321 control network module redundant link

BMENOC0321 control network module providing transparency between the device network and the control network

control network

Like the Hot Standby link, your choice of connector and wiring determines the maximum distance of the Ethernet physical link:

A copper wire link can extend a maximum distance of 100 m (328 ft).
A fiber optic single mode link can extend a maximum distance of 15 km (9.3 mi).