Schneider Electric Processor Adapter manual Network Design Considerations

Using the Ethernet Port

Network Design Considerations

Introduction In a distributed control environment, Ethernet can be used as:

λan I/O network

λa supervisory network

λa network that combines I/O and supervisory functions

This section discusses how to design your network to make communication between related devices as effective and deterministic as possible.

Note: Preserve your ARP cache information.

When installed on a new network, the M1 Ethernet Processor will obtain the MAC and IP addresses of other devices on the network. This process may require several minutes.

When the module is successfully communicating with these devices, if a ring adapter with battery back up is not present, it is recommended that you stop the processor and save the user program to flash. This will save the processor’s ARP cache and enable it to “remember” this information if power is lost or removed. If you do not save to flash the processor must repeat acquiring the ARP cache information from the network.

This procedure should also be followed whenever:

λA new or substitute device is installed on the network;

λThe IP address of a network device has been changed.

CAUTION

CONTROL NETWORKS MUST BE ISOLATED FROM MIS DATA NETWORKS

To maintain a deterministic Ethernet network, you must isolate Momentum Processor Adapters and related devices from MIS data networks. Traffic from MIS data networks can interrupt communication between control devices, causing your control application to behave unpredictably.

Additionally, the high message rates that may be generated between M1 Processors and I/O Adapters may bog down an MIS network, causing loss of productivity.

Failure to observe this precaution can result in injury or equipment damage.

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