daveInterface

A structure representing the physical connection to a PLC or a network of PLCs (e.g. like MPI). daveInterface stores all those properties that are common to a network of PLCs:
  • - The local address used by your computer.
  • - The speed used in this network.
  • - The protocol type used in this network.
  • - A name which is used when printing out debug messages.
    • The structure daveInterface is created and initialized by daveNewInterface: 
        daveInterface * di;
    di =daveNewInterface(fds, "IF1", localMPI, daveProtoXXX, daveSpeedYYY);
    The parameters are:
  • fds: a _daveOSserialType
  • a Name
  • localMPI: the address used by your computer/adapter (only meaningful for MPI and PPI)
  • daveProtoXXX: a constant specifying the protocol to be used on this interface
  • daveSpeedYYY: a constant specifying the speed to be used on this interface. (only meaningful for MPI and Profibus)

    • Protocol types to be used with newInterface:

    NameMeaning
    daveProtoMPIMPI for S7 300/400
    daveProtoMPI2MPI for S7 300/400, "Andrew's version"
    daveProtoPPIPPI for S7 200
    daveProtoISOTCPISO over TCP
    daveProtoISOTCP243ISO over TCP with CP243
    daveProtoIBHMPI with IBH NetLink MPI to ethernet gateway

    MPI/ProfiBus speed constants:

    daveSpeed9k
    daveSpeed19k
    daveSpeed187k
    daveSpeed500k
    daveSpeed1500k
    daveSpeed45k
    daveSpeed93k
    The name field is provided for applications which may communicate with multiple PLCs on multiple pgysical connections. In such cases, the name helps to tell which interface an error message comes from.