System and method for implementing an extended safety instrumented system
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. An apparatus comprising:
a processor configured to communicate data to another apparatus by attaching a sequence number and an authenticator to data to form a data unit, the processor further configured to replicate the data, the sequence number, and the authenticator of the data unit to provide a replicated data unit, and output both the data unit and the replicated data unit together in a single output message; and
a medium attachment unit, which translates the output message between the processor and a transmission medium.
2. The apparatus of claim 1 , wherein the processor is configured to generate the authenticator based upon a sequence number and the data.
3. The apparatus of claim 1 , wherein the processor is configured to generate the authenticator using the data and a connection key.
4. The apparatus of claim 1 , wherein the processor generates the authenticator using the data, a connection key, and an object index.
5. The apparatus of claim 4 , wherein the processor generates the authenticator by using a sequence number.
6. The apparatus of claim 1 , wherein the processor generates the authenticator using the data and a sub-index.
7. The apparatus of claim 1 , wherein the processor outputs the output message when the data is associated with a safety related function block.
8. The apparatus of claim 1 , further comprising at least one safety-related function block.
9. The apparatus of claim 8 , wherein the at least one safety-related function block receives analog input data.
10. The apparatus of claim 8 , wherein the at least one safety-related function block is an SISFB.
11. The apparatus of claim 1 , further comprising a memory adapted to store at least one non-safety-related function block.
12. The apparatus of claim 1 , further comprising a memory configured to store a plurality of function blocks, including a non-safety-related function block and a safety-related function block.
13. The apparatus of claim 12 , wherein the non-safety-related function block and the safety-related function block are interconnected to communicate data only from the safety-related function block to the non-safety-related function block.
14. The apparatus of claim 1 , wherein the transmission medium includes a digital bus.
15. The apparatus of claim 13 , wherein the transmission medium includes a High Speed Ethernet network.
16. The apparatus of claim 1 , wherein the processor is adapted for use with at least one of:
a safety-related resource block;
a first safety-related transducer block; and
a second safety-related transducer block.
17. The apparatus of claim 15 , wherein the safety-related resource block insulates a safety-related function block from physical hardware.
18. The apparatus of claim 15 , wherein the first safety-related transducer block decouples an input to a safety-related function block, and the second safety-related transducer decouples an output of the safety-related function block.
19. The apparatus of claim 1 , wherein the output message is at least CRC-32 compliant.
20. The apparatus of claim 1 , wherein the output message is at least SIL-1 compliant.
21. The apparatus of claim 1 , wherein the output message is at least SIL-3 compliant.
22. The apparatus of claim 1 , wherein the processor generates a virtual protocol data unit prior to communication of the output message.
23. The apparatus of claim 1 , wherein the transmission medium further comprises a black channel.
24. The apparatus of claim 22 , wherein the processor outputs an authenticator for transmission over the black channel.
25. The apparatus of claim 1 , further comprising a watchdog timer configured to monitor whether an output safety-related function block is timely executed.
26. The apparatus of claim 1 , further comprising a diagnostic transducer block.
27. The apparatus of claim 26 , wherein the diagnostic transducer block monitors the transmission medium for errors which may occur in the communication of messages between safety-related function blocks.
28. The apparatus of claim 26 , wherein the diagnostic transducer block monitors for at least one of timing errors, sequence errors, authentication errors masquerading errors, queuing errors and insertion errors.