Applies To:
  • CitectSCADA 2.10

Question: How do I setup Citect so that I can use the LAN redundancy?.

To use LAN redundancy the Local Area Network software must support multi NetBIOS protocol stacks. Citect will communicate with up to 4 NetBIOS protocol stacks at the same time allowing you to use up to 4 LAN cards with Citect. You could also use a single LAN card with 4 different NetBIOS protocol stacks or a combination of LAN cards and protocol stacks. As of this date Windows for Workgroups V3.11 is the only Network system which supports multi NetBIOS protocol stacks. This may change in the future, check with your network supplier.

To set up LAN redundancy you will need to configure all the LAN cards in Windows for Workgroups first. If you are using IPX to communicate with a Novell server then this protocol can only be configured once. You can configure multiple NetBEUI protocols however. You may run into problems when configuring the NetBEUI protocols as they must be all NDIS3 drivers. See Q1365 for information on setting this up.

Once you have the LAN cards properly installed and configured you must determine which LANA numbers are assigned to which protocols. The simplest way to do this is to look at your PROTOCOL.INI file. In here you will see which protocol and LAN card have been assigned to LANA numbers. These numbers will start at 0 and count up to the maximum number of protocols and LAN cards installed. Once you have this information you can configure Citect to use the multiple LAN's.

To do this edit your CITECT.INI file. Under the [LAN] heading put the parameter LANA= followed by the LANA numbers you wish Citect to use. For example:


This will tell Citect to first try LANA 0 to establish NetBIOS Sessions to the various servers it needs. If the Citect node cannot find the information it needs on this LANA then it will try the next one in the list, LANA 1, and then LANA 2 and then LANA 3. If Citect finds all it needs on LANA 0 and then LANA 0 becomes unusable Citect will start the polling process again with LANA 1 then LANA 2 etc.

If this Citect is configured as a Citect server then Citect will listen for Citect Clients on all the given LANA numbers at the same time. This allows a Citect server to have Citect clients distributed across all network cards at the same time (pretty cool ha!).

If you are using Novel NetWare your connection to the file server does not support redundancy of the LAN cards. This is a limitation of the Novell Netware client. Because of this limitation if the LAN card or network which Novell Netware is using fails and there are vital files Windows needs on the Netware file server, then the computer will fail.

Windows for Workgroups file servers do not have this limitation. If Windows for Workgroups is accessing files on another WFW file server or a Windows NT file server and that LAN or Network card fails, WFW will try to establish a session via the other LAN card. Because of this feature WFW 3.11 is currently the best platform if you require LAN redundancy.