SuiteLink Overview With the advent of FactorySuite 2000, the Wonderware I/O Server Toolkit now provides SuiteLink, a proprietary communication protocol that can be used as in addition to DDE or as an alternative to DDE. Generally speaking, the SuiteLink protocol works much like the Wonderware FastDDE protocol: - The sender allocates a block of memory and fills it with a sequence of items detailing events and data. Events/commands include the following: - “Registering” a point (assigning a handle or ID number) - “Advising” a point for continuous update - “Requesting” the current value of a point - Writing a value to a point - Providing new polled data for a point - “Unadvising” a point - “Unregistering” a point - Acknowledging a command, indicating success or failure - The SuiteLink transport moves the contents of this block from the sender to the receiver. - The receiver then interprets the block of events, performs the indicated operations, and creates a response block of ACKs, Nacks, data, etc. - The SuiteLink transport moves the contents of the response block to the original sender. The main difference is that SuiteLink uses TCP/IP sessions as a transport instead of Dynamic Data Exchange (DDE). Where an I/O Server is concerned, the type of communication channel between client and server is transparent. That is, the serverspecific code does not know – and does not need to know to know – whether a client is connected via DDE or via SuiteLink. The following are some of the features SuiteLink offers over DDE: - Performance optimizations for networked installations with large fan-in and fan-out network node count requirements. - Reduced interaction between connections when an outage or delay occurs on one of the connections. - Better diagnostic and monitoring capability. - Transport of value, time, quality (VTQ) information. - Use of standard TCP/IP session based transport at fixed port address (5413) to enable deployment over WAN intranet, RAS dial-up, or Internet if desired. The following factors may make the continued deployment of DDE/NetDDE preferable in some installations: - When client and server are on the same PC, DDE may offer reduced data reporting latency under conditions of low data item counts combined with high (> once per second) data change rates. - When client and server are on different PCs, but on the same subnet, and NetBUI is configured as the NetDDE transport, NetDDE may offer reduced data reporting latency under conditions of low data item counts combined with high (> once per second) data change rates. A server built with the I/O Server Toolkit will automatically support both SuiteLink and DDE/NetDDE connections. Both varieties of connections can be used simultaneously.