System and method for implementing safety instrumented systems in a fieldbus architecture
An apparatus, system and process is provided for communicating safety-related data, over an open system, from a sender to a receiver. Safety-related components, including function blocks, flexible function blocks, resource blocks and transducer blocks, as well as, safety-related objects are provided. Also, an extended safety-related protocol provides for authenticating communications between safety-related components over an existing black channel, such as one using a fieldbus Architecture.
1. A system for permitting interoperability between safety and non-safety devices in a block-oriented open control system comprising:
a first device comprising
a memory, which includes at least one safety component, the safety component including a safety resource block and a safety function block, the safety resource block configured to uniquely identify a safety resource in the first device and the safety function block configured to process parameters associated with the safety resource to produce an output message, the safety component configured to store at least one safety parameter, the safety component configured to lock to prevent a change to the safety parameter while the safety component is online, the safety component further configured to utilize a virtual communication relationship for communication with a second component and to communicate using an extended safety protocol including maintain an expected sequence number and check a received sequence number against the expected sequence number; and
a processor, operably connected to the memory, wherein the processor executes the safety component based on a system schedule;
a second device including a non-safety component;
a first medium attachment unit, coupled for communication to the safety component, the first medium attachment unit configured to translate an input message from a transmission medium to the safety component and the output message from the safety function block to the transmission medium using an extended safety protocol; and
a second medium attachment unit, coupled for communication to the non-safety component, the second medium attachment unit configured to translate messages between the transmission medium and the non-safety component without an extended safety protocol.
2. A system according to claim 1 wherein the safety component is further configured to deny write access while the safety component is locked.
3. A system according to claim 2 wherein the safety component is further configured to accept a read request communicated without the extended safety protocol.
4. A system according to claim 3 wherein the safety component is configured to accept the read request while the safety component is locked.
5. A system according to claim 1 wherein the safety component includes a transducer block configured to process data received from or destined for a field device coupled for communication to the safety component.
6. A system according to claim 1 wherein the safety component is configured to communicate with a second safety component using the extended safety protocol.