Software package for the development of safety nodes (SN)
and Safety Configuration Manager (SCM)

The openSAFETY protocol stack is an implementation of the openSAFETY specification version 1.1.0 and is provided free of charge by B&R under a BSD license. The protocol stack was developed by IXXAT together with B&R and is used for B&R products, which are already SIL-3 certified. The protocol stack can be downloaded free of charge from the IXXAT webpage .


Highlights

• Scope of functions based on the current openSAFETY specification V 1.1.0
• Modular software structure for the implementation of SN (Safety Slave) and SCM (Safety Master)
• Clearly structured programming interface for connection of the application program
• “C”-source code for use on any target platforms (hardware-independent)
• Independent of operating system – can be run with and without operating system
• Simple connection to a non-safe transport protocol possible via abstraction layer
• Any non-safe transport protocol can be used according to the black channel principle (e.g. POWERLINK, TPC/IP or any other industrial Ethernet Protocol)
• Multi-instancibility allows simple creation of safety domain gateways
• Reference portation for Intel Xscale (IXP420) and Atmel ARM7 (AT91SAM7S64) for GNU C-Compilers
• Designed for use in SIL-3 devices
• PC demo included

Overview

SSC:	Safety Stack Control: control of the openSAFETY software such as stack initialisation
SNMT:	Safety Network Management: transmission, reception and processing of network management commands as well as distribution of the safety addresses
SCM:	Safety Configuration Manager: configuration, verification and monitoring of safety nodes
SPDO:	Safety Process Data Objects: cyclic exchange of process data and verification of time synchronization
SSDO:	Safety Service Data Objects: server/client communication to access the object directory via the network
SOD:	Safety Object Dictionary: access to the Safety Object Directory
SFS:	Safety Frame Serialization: serialization and deserialization of the safety frames
SNS:	Safety Node State: management of the operating states of the safety nodes
SERR:	Safety Error Handling: logging of stack-internal errors
SCFM:	Safety Control Flow Monitoring: monitoring of the correct program flow in accordance with SIL-3

Hardware concepts for openSAFETY
The Safety Integrity Level (SIL) that can be achieved with the openSAFETY software mainly depends on the hardware architecture used. The openSAFETY software was created for use in SIL-3 devices. To meet the requirements of SIL-1, it is sufficient for example to use one single Safety Controller (SC) that carries out the safe application and the openSAFETY stack. To achieve SIL-3, the Safety Controller must also be designed as redundant.

 

Overview of functions
With its function modules, the openSAFETY software enables the execution of all communication and back-up mechanisms necessary for openSAFETY. This includes the provision of a Safe Object Directory (SOD), Safe Process Data (SPDO) and Safe Service Data (SSDO) as well as time and CRC monitoring of the data packages.

Zipping and unzipping of the openSAFETY frames in the transmission messages of the non-safe transmission protocol is carried out by the functions of the hardware-level firmware (SHNF) provided by the user. The inputs and outputs of the openSAFETY device must also be controlled by a special safety application. The SOD of the openSAFETY software is used as the data interface to the safety application.

Scope of supply

• C-source code of the openSAFETY protocol stack
• C-source code of the unit tests
• Reference portation for Intel XSscale (IXP420) and Atmel ARM7 (AT91SAM7S64) for GNU C compiler
• Manual

Supplementary services

• Support
  IXXAT offers technical support within the scope of an extra charged maintenance contract. This includes technical support and consultation regarding the use of openSAFETY preferably by e-mail or the direct support by a developer at IXXAT or at customer site.
   
• Technical support
  Consultation regarding the usage of openSAFETY as well as concept and specification questions for safety relevant product or system solution.
   
• Hardware and software development services
  As development partner we support you at the implementation and portation of openSAFETY, at the development of safety applications and safety hardware as well as at the certification. At this, you can benefit from our comprehensive openSAFETY know-how and our competence in the development of safety hardware and software.