Support for Standalone and Hot Standby PACs

An M580 safety system supports SIL3 applications for standalone and Hot Standby PACs. Each CPU rack includes a CPU and a coprocessor module.

NOTE: For a description of available racks and their permitted usage refer to the topic Rack Usage.

Placing Safety Modules in the RIO Main Ring

Install M580 safety modules only in the RIO main ring, which includes:

  • The local main rack. Standalone safety PACs can also include up to seven optional local extended racks.

    • The local main rack must include a safety power supply, a safety CPU, and a safety coprocessor.

    • For a standalone safety PAC, the local main rack and the local extended racks may also include safety I/O. An M580 Hot Standby PAC does not support I/O on the local main rack, or local extended racks.

    NOTE: The maximum distance between the main rack and the last extended rack is 30 m.

  • Up to 31 RIO drops for the BME•586040S CPU, 16 RIO drops for the BME•584040S CPU, and 8 RIO drops for the BME•582040S CPU), each consisting of a remote main rack and an optional remote extended rack.

Any rack with safety modules also requires a safety power supply.

NOTE: A rack that includes safety modules may also include type 1 non-interfering modules. However, type 2 non-interfering modules may not be placed on the same rack as safety modules. Type 2 non-interfering modules may be placed on racks without safety modules–for example, in racks of distributed equipment. Other non-safe modules may not be included in an M580 safety system.

Extending a Main Rack

Use BMXXBE1000 rack extender modules to daisy chain together main and extended racks. Connect each pair of extender modules using BMXXBC•••K connector cables, and terminate each end of the chain with TSXELYEX line terminators.

Local Rack Communications with an RIO Drop

To support RIO drops in an M580 safety system with CPU firmware 3.10 or earlier, configure the M580 safety CPU as an NTP server, or as an NTP client (with another device configured as an NTP server). Without a properly set up clock (NTP), safety I/O communication may not operate correctly.

Use a BM•CRA312•0 remote adapter module (a BM•CRA31200 for a remote rack hosting Non Interfering only modules, and a BM•CRA31210 adapter for remote rack hosting both non-interfering and/or safety I/O modules to connect the RIO drop to the RIO main ring. Connect each end of the RIO main ring to the two dual ports on the BME•58•040S safety CPU.

If the connection is made via Cat5e copper cable, the maximum distance between drops is 100 m.

NOTE: Alternatively, you can connect the local main rack to the BM•CRA312•0 remote adapter in the RIO drop by placing a BMXNRP020• fiber optic repeater module into each rack. Refer to the topic Using Fiber Converter Modules in the Modicon M580 Standalone System Planning Guide for Frequently Used Architectures for additional information.

Connecting Two M580 Safety PACs

A M580 safety system also supports peer-to-peer black channel communication between two safety PACs. Typically, this connection is made via a BMENOC0321 in each safety system. Refer to the peer-to-peer communications topic in the Modicon M580 Safety Manual for more information.

NOTE: To support black channel communications between two PACs with CPU firmware 3.10 or earlier, enable the NTP service in both PACs. You can configure one PAC as the NTP server, and the other as the NTP client. Alternatively, you can configure each PAC as an NTP client, with another device configured as NTP server.

Adding Distributed Equipment to an M580 Safety System

You can include distributed equipment in your M580 safety system. Typically, distributed equipment is connected as either non-looping daisy chain, or a daisy chain loop.

You can connect a distributed equipment daisy chain loop to the two network ports of one of the following modules on the RIO main ring:

  • a BMENOC0301/11 Ethernet communications module.

  • a BMENOS0300 Ethernet network option switch.

  • a ConneXium dual ring switch.

You can also use the service port of a BMENOC0301/11 Ethernet communications module, a BMENOS0300 Ethernet network option switch or the BME•58•040S safety CPU to connect distributed equipment in the shape of a non-looping daisy chain.

NOTE: Place only type 1 and type 2 non-interfering modules in a distributed equipment network. Place safety modules only in the local rack (main or extended) and the RIO network. Exclude non-safe modules that are not type 1 or type 2 non-interfering modules from your safety project.

Refer to the topic Selecting the Correct Topology in the Modicon M580 Standalone System Planning Guide for Frequently Used Architectures for additional information on connecting distributed equipment to an M580 CPU.

Adding CIP Safety Equipment to the M580 Safety System

You can include CIP Safety I/O (CSIO) devices in your M580 safety system as CSIO distributed equipment.

You can connect CSIO distributed equipment to the RIO main ring through:

  • the service port of a CPU or a BM•CRA31210 X80 EIO adapter module.

  • a BMENOS0300 Ethernet network option switch.

  • a ConneXium Dual Ring Switch (DRS).

Each type of I/O (CSIO, RIO, DIO) has its own limitation. To maintain an acceptable level of performance, it is recommended not to use the maximum of all I/O types in the same architecture.

It is recommended that a typical M580 CIP Safety architecture is based on a remote or distributed topology:

Remote topology recommended limitations:

CSIO Devices

DIO Devices

RIO Drops

BMEP582040S

10

10

8

BMEP584040S

32

10

16
BMEP586040S

(nb CSIO) + 0.5*(nb DIO) + (nb RIO) ≤ 128

Distributed topology recommended limitations:

CSIO Devices

DIO Devices

RIO Drops

BMEP582040S

16

61

2

BMEP584040S

64

61

2
BMEP586040S

(nb CSIO) + 0.5*(nb DIO) + (nb RIO) ≤ 128

The CSIO time contribution to the SAFE task is roughly 100 µs/equipment with a BMEP584040S or BMEP586040S CPU and 400 µs/equipment with a BMEP582040S CPU.