Joined Client Server Network & Control Network
Hi to All
is it necessary to have separated Control Network and Client/Server Network?
Is it Possible to Join the Control Network and Client/Server Network together?
What about Same phisical network for Control,Client/Server and Fieldbus(HSE,...) Networks?
What is advantages or defects of each config?
Thanks a lot.
Please read the System 800xA, Automation System Network User's Guide.
It's indeed possible to have controllers on the client/server network, a so called "collapsed network". Theoretically, you can have more stuff running there as well.
With adequate network hardware (industrial graded switches) you can have plenty of traffic on the network separated by different subnets (172.16.4.0/22, 192.168.1.0/24, etc). The switches will see to that only telegrams addressed to the controllers will be sent there.
The advantage is of course the savings in hardware.
A disadvantage is loss of separation; a controller is not suited to be connected to a network with lots of broadcast and multicast (which are sent to all nodes). The AC 800M has a built-in network filter which attempts to block telegrams of types it should not handle, still such traffic will drain resources from the controller's network hardware (all but PM891 running 10 mbit/second half duplex).
Depending on the application, a collapsed network can be suitable, still there are high availability applications where it does not fit in.
There are several reasons to have seperate networks which are very well covered by networing manual. Below is a quick extract for your reference.
Fault isolation. An erroneous network segment on Client/Server Network will not affect nodes on the Control Network.
Limitation of broadcast traffic. Broadcasts on Client/Server Network will not disturb the real-time traffic on the Control Network
Traffic filtering. Undesired traffic can be blocked by the Connectivity Servers. The Control Network is more secure if it is isolated from the Client Server Network.
The network is distributed over large distances using link protocols with different network characteristics.
The IP routing resources (Routing table, ARP table or CPU power etc.) in a single node are not large enough to handle a large number of nodes on the same Network Area.