The C2C network concept (controller-to-controller coupling network concept) allows you to align several machines or to build machines consisting of multiple controllers, by synchronized precision of velocity and position information between different controllers.
This chapter describes the general approach and architecture of the C2C network concept, as well as its use and configuration in the automation software EcoStruxure Machine Expert.
NOTE: C2C network can be a functional replacement for the encoder network.
For further information, refer also to Migration notes for users of hardwired encoder coupling or encoder network.
NOTE: C2C participants must use the same EcoStruxure Machine Expert version. In case of incompatible versions the system indicates the diagnostic message 8509.
The main characteristics of the C2C network are:
oSynchronization of multiple PacDrive LMCs via Sercos
oExchange of encoder signals and application data between several PacDrive LMCs
oMaster as well as slave can function as producer.
The main tasks of the C2C network are:
oSynchronous exchange of data
oProviding virtual encoder signals which can be used for machine coupling
oSynchronizing the Sercos clock between the different Sercos networks
The C2C network concept consists of the following two layers:
oIn the first layer, the Sercos networks of different PacDrive LMCs are synchronized.
This synchronization follows a master/slave concept.
That means, in each C2C network, one PacDrive LMC is the C2C Master and the other PacDrive LMCs are the C2C Slaves.
oIn the second layer, signals (encoder signals and application data) are exchanged in a synchronized manner.
For this purpose, the following producer-consumer concept is used:
oSignals are transmitted from producers to consumers.
oFor each signal, which is transmitted in a C2C network, one unique ID exists.
oFor one signal, one producer and 1..n consumers exist in the C2C network.
oProducers and consumers are represented by C2C data objects:
producer data objects: C2C Data Output, C2C Encoder Output
consumer data objects: C2C Data Output, C2C Encoder Input
oThe assignment of producer and consumer data objects is realized by setting the parameter ID to the same value.
oThe C2C network distributes the signals of a producer to all consumers with the same ID.
The main points of the C2C network are:
oIn every C2C network, one PacDrive LMC is the C2C Master, the other PacDrive LMCs are the C2C Slaves.
oThe C2C Slave PacDrive LMCs are added as Sercos Slave devices into the Sercos network of the C2C Master. In addition, every C2C Slave acts as a Sercos Master in its own Sercos network. Each of these Sercos networks can have its own devices (drives, I/O modules).
oThis means that there are cascaded Sercos networks where the C2C Master is the Sercos Master of the superordinate network and the C2C Slaves are Sercos Master of their respective sub-network.
The following objects are used in EcoStruxure Machine Expert to configure the C2C network:
oC2C Master object
The object is added to the project file of the C2C Master PacDrive LMC to signal that this PacDrive LMC is the C2C Master.
oC2C Slave object:
The object is added to the project file of the C2C Slave PacDrive LMC to signal that this PacDrive LMC is a C2C Slave.
oLogic Motion Controller Device object:
This object is added to the Sercos Master object in the project file of the C2C Master to represent the C2C Slaves as Sercos Slave devices in the Sercos network of the C2C Master.
oThe data transmitted in the C2C network is represented by the following objects:
oC2C Data Input object
oC2C Data Output object
oC2C Encoder Input object
oC2C Encoder Output object
These objects can be added below the C2C Master object or the C2C Slave object.
