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.

Key Features

• Isochronous produce and consume of cyclic data (SCP_Sync)
• UC channel for transmission and reception of non-SIII-Ethernet-frames (SCP_NRTPC)
• Diagnostic Trace Buffers (GDP DiagT)

Supported Protocols

• SIP - SercosinternetProtocol

Protocol Technical Data

Restrictions

• Max. 2 connections: 1 for consumer and 1 for producer
• Modifications of the Service-Channel Object Dictionary are volatile after reset (if resides on device)
• Cross communication not supported yet
• UCC Communication: Second DPM Channel (“Ethernet Interface Task”) is not available on all hardware
• Clock parameters ulDTDivClk  (Contents of DTDivClk register) and ulDivClkLength  (DivClk Length) are no longer adjustable (since V3.1). ulDivClkLength is now always set to the fixed value 1 μs. In Div_Clk mode 0 it is not possible any more to configure aperiodic signals. ulConClkLength has now a maximum of 655350 ns.

For more information please see the product manual.

Firmware Functions

The real-time protocol stack is fully integrated into a netX firmware for specific use case in order to provide a common set of netX firmware functions accross different protocol variants:

Firmware Variants	Use Case A	Use Case B	Use Case C
Use Case summary	netX90 COM CPU firmware for small footprint, low cost and function optimized slave devices no external SPI / SQI Flash required for COM CPU no external SDRAM required for COM CPU	same as Use Case A, but netX90 APP CPU uses external SPI Flash may use external SDRAM	full featured firmware for highest function requirements external SDRAM is required for COM CPU external SPI Flash is required for COM CPU
netX support	netX90	netX90 with ext FLASH	netX90 with ext SDRAM and ext FLASH
FW structure
Host Interface	Dual Port Memory interface with following channels: Channel 0 - Real-Time Ethernet Protocol API exchange cyclic IO data use acyclic protocol services Channel 1 - Network Services Socket API - Enables opening a communication socket using the integrated TCP/IP stack resources, i.e. same MAC address Ethernet (NDIS) API - Enables sending and receiving Ethernet frames using a separate MAC address, i.e. application host with its own TCP/IP stack Web API - Enables forwarding specific URL (HTTP GET/POST) requests to user applications, e.g. to build custom webpage contents
Diagnostic Interface	netX Diagnostic and Remote Access is supported via COM UART
Integrated Flash File System	N/A	N/A	power-fail safe flash file system on external SPI flash
Remanent Data Storage	Power-fail safe storage of up to 16KB of protocol remanent data in netX90 internal flash		Power-fail safe storage of protocol remanent data in dedicated partition in extenal SPI flash. Size and position of remanent storage area shall be configured in FDL.
Device Data	device production data (Serial number, MAC address, production data etc.) shall be stored in FDL in netX90 internal flash
Firmware Transfer	to internal netX90 flash ... via integrated web server via Host Interface (DPM, SPM) Note: due to limited size (max. 380KB) of FW update area in internal flash, only following files can be transfered: individual firmware files (i.e. comfw.nxi or appfw.nai) if the size of the a file is less that 380KB max. 380KB big FWUPDATE.zip file with predefined structure	to the host application... via integrated webserver and Web API  (DPM Channel 1) host application need to handle storage of the firmware in external SPI flash	to netX flash file system located on external SPI Flash
Firmware Update	Firmware check and installation supported through calling the Maintenance Firmware
	from internal netX90 flash	from external SPI flash	from Flash File System located on external SPI Flash
Configuration	by sending configuration packets to the firmware via Host Interface
	N/A	N/A	or by using Communication Studio configuration database file from local flash file system
Integrated Basic Webserver	The basic web server has the following features: \netx  - Provides a graphical user interface to other functions (diag, firmware, reset, etc.)       \netx\diag  - Provides information on the netX device (current uptime, MAC address, device   number, serial number, etc. \netx\firmware  - Enables uploading a new firmware update file to netX flash \netx\reset  - Initiates a netX reset cycle, i.e. to install a newly uploaded firmware \  - URL requests are forwarded to the user application via DPM (web interface API)
Webserver extension	N/A	N/A	Basic web server is extended with functions that provide access to the content files on a local Flash file system (SQI Flash). \netx\files  - Enables streaming of custom web content according to media types (i.e. txt, js, xhtml, jpeg, json, etc.) located in the Flash file system
Tag List Options	Firmware supports certain modification of the functionality via Tag List, in particular: Webserver port number or deactivation Activation of Ethernet Interface in DPM Channel1 Selection of target for remanent data storage (netX local or external host) Profinet protocol stack configuration parameters
HW Sync Signal	supported via netX signal XC_TRIGGER0/1
Protocol Specific LED Indicators	Network specific status indicators with COM0 / COM1 LEDs: Sercos LED
Secure Boot	supported by Sercos Slave V5.2.0.0 and later, see Support of Secure Boot with netX90 for more details
Limitations	FW functions are limited by available internal RAM / Flash COM firmware size is limited to max. 500KB	FW functions are limited by available internal RAM / Flash COM firmware size is limited  to max. 880KB