Description - V3
Description
The Sercos slave stack has implemented the required state machines and services to build a Sercos slave device. It can be used to build a complete Sercos slave device which requires a correctly behaving application.
The stack on its own just provides services that need to be handled correctly by an application for certification and correct behaviour in the field, e. g. remanent storing of the sercos slave address.
Configuration
The stack offers a mailbox interface for configuration. The configuration has to be set using a Set Configuration packet first.
Cyclic data and I/O state
The stack offers an interface to access the cyclic data as well as a packet based interface for configuration and acyclic services.
The cyclic data is either accessed using special callback functions when the application is running directly on netX chip or cyclic data is available in the dual-port memory which can be accessed by a host application.
The stack supports different ways of handling the Connection Control, IO Control and IO Status. All can get handled by stack or by the application. In case the stack handles them they are always set to "valid".
Acyclic services
Acyclic services requests through the Master are indicated to a registered application via the mailbox interface. E.g. an IDN access through the master via service channel or SIP can get reported to the application. Also changes in communication phase, topology or network settings will be reported. An application can register diagnosis messages/codes which are handled by stack and reported in the corresponding IDNs and trace buffers to the master.