Schneider Electric Processor Adapter - Manual (Page 144)

Using the Ethernet Port
870 USE 101 10 V..2 144
Network Design Considerations
Introduction In a distributed control environment, Ethernet can be used as:
l an I/O network
l a supervisory network
l
a 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.
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:
l A new or substitute device is installed on the network;
l The IP address of a network device has been changed.
Continued on next page
Note: Preserve your ARP cache information.
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.