2009 IEEE International Conference on Industrial Technology, 2009
Current trends in the manufacturing sector have greatly increased the need for portability and re... more Current trends in the manufacturing sector have greatly increased the need for portability and reusability in software systems for industrial control and automation. The IEC 61499 standard has emerged out of this need for a platformindependent way to develop industrial control systems. So far, typical IEC 61499 solutions have relied on some run-time environment that differ in the execution model for each implementation. This has resulted in code that is neither portable, nor efficient in terms of execution speed and memory footprint. Therefore, we present, instead, a synchronous model for function blocks, which removes the need for a run-time environment by making all event scheduling decisions during compile-time. This approach has been used to create a function block compiler, with two different back-end code generators. We present experimental results of a benchmark suite implemented using different code generators for different execution models, and show that our technique yields significant gains in efficiency over existing approaches.
Implementing constrained cyber-physical systems with IEC 61499
ACM Transactions on Embedded Computing Systems, 2012
Cyber-physical systems (CPS) are integrations of computation and control with sensing and actuati... more Cyber-physical systems (CPS) are integrations of computation and control with sensing and actuation of the physical environment. Typically, such systems consist of embedded computers that monitor and control physical processes in a feedback loop. While modern electronic systems are increasingly characterized as CPS, their design and synthesis still rely on traditional methods, which lack systematic and automated techniques for accomplishment. Recently, IEC 61499 has been proposed as a standard for designing industrial process-control and measurement systems. It prescribes a component-based approach for developing industrial automation software using function blocks. Executable code can then be automatically generated and simulated from these function blocks. This bodes well for designers of CPS, who are more likely to be experts in specific industrial domains, rather than in computer science. The intuitive graphical nature and automatic code synthesis of IEC 61499 programs will alle...
IEC 61499 has been endorsed as the standard for modelling and implementing distributed industrial... more IEC 61499 has been endorsed as the standard for modelling and implementing distributed industrial-process measurement and control systems. The standard prescribes the use of function blocks for designing systems in a componentoriented approach. The execution model of a basic function block and the manner for event/data connections between blocks are described therein. Unfortunately, the standard does not provide exhaustive specifications for function block execution. Consequently, multiple standard-compliant implementations exhibiting different behaviours are possible. This not only defeats the purpose of having a standard, but makes verification of function block systems difficult. To overcome this, we propose synchronous semantics for function blocks, and show its feasibility by translating function blocks into a subset of Esterel, a wellknown synchronous language. The proposed semantics avoids causal cycles common in Esterel, and is proven to be reactive and deterministic under any composition. Moreover, verification techniques developed for synchronous systems can now be applied to function blocks.
Electronic Notes in Theoretical Computer Science, 2009
We propose a fully pipelined, multithreaded, reactive processor called STARPro for direct executi... more We propose a fully pipelined, multithreaded, reactive processor called STARPro for direct execution of Esterel. STARPro provides native support for Esterel threads and their scheduling. In addition, it also natively supports Esterel's preemption constructs, instructions for signal manipulation, and a notion of logical ticks for synchronous execution. As a side effect of the proposed architecture, we have developed a new intermediate format called UCCFGs d (unrolled concurrent control-flow graph with surface and depth) that closely resembles the Esterel source. A compiler based on UCCFGs d , has been developed for code generation. We have synthesized STARPro and have carried out a range of benchmarking experiments. Experimental results reveal substantial improvement in performance and code size compared to software compilers. We also excel in comparison to recent reactive architectures, by achieving an average speed-up of 37% in worst-case reaction times, and a speed-up of 38% in average-case reaction times. This has been achieved by utilizing fewer hardware resources, while incurring an average code size increase of 40%.
Synchronous execution of IEC 61499 function blocks using Esterel
The IEC 61499 standard proposes a component-oriented approach for specifying industrial-process m... more The IEC 61499 standard proposes a component-oriented approach for specifying industrial-process measurement and control systems using function blocks. Unfortunately, the standard does not provide rigorous semantics for the execution of function blocks, resulting in different behaviours on different implementations. The differences arise mostly as a result of the various event handling and scheduling mechanisms employed. To overcome such ambiguities, this
We propose a fully pipelined, multithreaded, reactive processor called STARPro for direct executi... more We propose a fully pipelined, multithreaded, reactive processor called STARPro for direct execution of Esterel. STARPro provides native support for Esterel threads and their scheduling. In addition, it also natively supports Esterel's preemption constructs, instructions for signal manipulation, and a notion of logical ticks for synchronous execution. In addition to the reactive processors, we propose a new intermediate format called UCCFG sd (unrolled concurrent control-flow graph with surface and depth) that closely resembles the Esterel source. A compiler based on UCCFG sd , has been developed for code generation. We have synthesized STARPro and have carried out a range of benchmarking experiments. Experimental results reveal substantial improvement in performance and code size compared to software compilers. We also excel in comparison to recent reactive architectures, by achieving an average speed-up of 37% in worst-case reaction times, and a speed-up of 38% in averagecase reaction times. This has been achieved by utilizing fewer hardware resources, while incurring an average code size increase of 40%.
IEC 61499 has been endorsed as the standard for modelling and implementing distributed industrial... more IEC 61499 has been endorsed as the standard for modelling and implementing distributed industrial-process measurement and control systems. The standard prescribes the use of function blocks for designing systems in a componentoriented approach. The execution model of a basic function block and the manner for event/data connections between blocks are described therein. Unfortunately, the standard does not provide exhaustive specifications for function block execution. Consequently, multiple standard-compliant implementations exhibiting different behaviours are possible. This not only defeats the purpose of having a standard, but makes verification of function block systems difficult. To overcome this, we propose synchronous semantics for function blocks, and show its feasibility by translating function blocks into a subset of Esterel, a wellknown synchronous language. The proposed semantics avoids causal cycles common in Esterel, and is proven to be reactive and deterministic under any composition. Moreover, verification techniques developed for synchronous systems can now be applied to function blocks.
Electronic Notes in Theoretical Computer Science, 2009
We propose a fully pipelined, multithreaded, reactive processor called STARPro for direct executi... more We propose a fully pipelined, multithreaded, reactive processor called STARPro for direct execution of Esterel. STARPro provides native support for Esterel threads and their scheduling. In addition, it also natively supports Esterel's preemption constructs, instructions for signal manipulation, and a notion of logical ticks for synchronous execution. As a side effect of the proposed architecture, we have developed a new intermediate format called UCCFGs d (unrolled concurrent control-flow graph with surface and depth) that closely resembles the Esterel source. A compiler based on UCCFGs d , has been developed for code generation. We have synthesized STARPro and have carried out a range of benchmarking experiments. Experimental results reveal substantial improvement in performance and code size compared to software compilers. We also excel in comparison to recent reactive architectures, by achieving an average speed-up of 37% in worst-case reaction times, and a speed-up of 38% in average-case reaction times. This has been achieved by utilizing fewer hardware resources, while incurring an average code size increase of 40%.
2009 IEEE International Conference on Industrial Technology, 2009
Current trends in the manufacturing sector have greatly increased the need for portability and re... more Current trends in the manufacturing sector have greatly increased the need for portability and reusability in software systems for industrial control and automation. The IEC 61499 standard has emerged out of this need for a platformindependent way to develop industrial control systems. So far, typical IEC 61499 solutions have relied on some run-time environment that differ in the execution model for each implementation. This has resulted in code that is neither portable, nor efficient in terms of execution speed and memory footprint. Therefore, we present, instead, a synchronous model for function blocks, which removes the need for a run-time environment by making all event scheduling decisions during compile-time. This approach has been used to create a function block compiler, with two different back-end code generators. We present experimental results of a benchmark suite implemented using different code generators for different execution models, and show that our technique yields significant gains in efficiency over existing approaches.
2009 IEEE International Conference on Industrial Technology, 2009
Current trends in the manufacturing sector have greatly increased the need for portability and re... more Current trends in the manufacturing sector have greatly increased the need for portability and reusability in software systems for industrial control and automation. The IEC 61499 standard has emerged out of this need for a platformindependent way to develop industrial control systems. So far, typical IEC 61499 solutions have relied on some run-time environment that differ in the execution model for each implementation. This has resulted in code that is neither portable, nor efficient in terms of execution speed and memory footprint. Therefore, we present, instead, a synchronous model for function blocks, which removes the need for a run-time environment by making all event scheduling decisions during compile-time. This approach has been used to create a function block compiler, with two different back-end code generators. We present experimental results of a benchmark suite implemented using different code generators for different execution models, and show that our technique yields significant gains in efficiency over existing approaches.
Implementing constrained cyber-physical systems with IEC 61499
ACM Transactions on Embedded Computing Systems, 2012
Cyber-physical systems (CPS) are integrations of computation and control with sensing and actuati... more Cyber-physical systems (CPS) are integrations of computation and control with sensing and actuation of the physical environment. Typically, such systems consist of embedded computers that monitor and control physical processes in a feedback loop. While modern electronic systems are increasingly characterized as CPS, their design and synthesis still rely on traditional methods, which lack systematic and automated techniques for accomplishment. Recently, IEC 61499 has been proposed as a standard for designing industrial process-control and measurement systems. It prescribes a component-based approach for developing industrial automation software using function blocks. Executable code can then be automatically generated and simulated from these function blocks. This bodes well for designers of CPS, who are more likely to be experts in specific industrial domains, rather than in computer science. The intuitive graphical nature and automatic code synthesis of IEC 61499 programs will alle...
IEC 61499 has been endorsed as the standard for modelling and implementing distributed industrial... more IEC 61499 has been endorsed as the standard for modelling and implementing distributed industrial-process measurement and control systems. The standard prescribes the use of function blocks for designing systems in a componentoriented approach. The execution model of a basic function block and the manner for event/data connections between blocks are described therein. Unfortunately, the standard does not provide exhaustive specifications for function block execution. Consequently, multiple standard-compliant implementations exhibiting different behaviours are possible. This not only defeats the purpose of having a standard, but makes verification of function block systems difficult. To overcome this, we propose synchronous semantics for function blocks, and show its feasibility by translating function blocks into a subset of Esterel, a wellknown synchronous language. The proposed semantics avoids causal cycles common in Esterel, and is proven to be reactive and deterministic under any composition. Moreover, verification techniques developed for synchronous systems can now be applied to function blocks.
Electronic Notes in Theoretical Computer Science, 2009
We propose a fully pipelined, multithreaded, reactive processor called STARPro for direct executi... more We propose a fully pipelined, multithreaded, reactive processor called STARPro for direct execution of Esterel. STARPro provides native support for Esterel threads and their scheduling. In addition, it also natively supports Esterel's preemption constructs, instructions for signal manipulation, and a notion of logical ticks for synchronous execution. As a side effect of the proposed architecture, we have developed a new intermediate format called UCCFGs d (unrolled concurrent control-flow graph with surface and depth) that closely resembles the Esterel source. A compiler based on UCCFGs d , has been developed for code generation. We have synthesized STARPro and have carried out a range of benchmarking experiments. Experimental results reveal substantial improvement in performance and code size compared to software compilers. We also excel in comparison to recent reactive architectures, by achieving an average speed-up of 37% in worst-case reaction times, and a speed-up of 38% in average-case reaction times. This has been achieved by utilizing fewer hardware resources, while incurring an average code size increase of 40%.
Synchronous execution of IEC 61499 function blocks using Esterel
The IEC 61499 standard proposes a component-oriented approach for specifying industrial-process m... more The IEC 61499 standard proposes a component-oriented approach for specifying industrial-process measurement and control systems using function blocks. Unfortunately, the standard does not provide rigorous semantics for the execution of function blocks, resulting in different behaviours on different implementations. The differences arise mostly as a result of the various event handling and scheduling mechanisms employed. To overcome such ambiguities, this
We propose a fully pipelined, multithreaded, reactive processor called STARPro for direct executi... more We propose a fully pipelined, multithreaded, reactive processor called STARPro for direct execution of Esterel. STARPro provides native support for Esterel threads and their scheduling. In addition, it also natively supports Esterel's preemption constructs, instructions for signal manipulation, and a notion of logical ticks for synchronous execution. In addition to the reactive processors, we propose a new intermediate format called UCCFG sd (unrolled concurrent control-flow graph with surface and depth) that closely resembles the Esterel source. A compiler based on UCCFG sd , has been developed for code generation. We have synthesized STARPro and have carried out a range of benchmarking experiments. Experimental results reveal substantial improvement in performance and code size compared to software compilers. We also excel in comparison to recent reactive architectures, by achieving an average speed-up of 37% in worst-case reaction times, and a speed-up of 38% in averagecase reaction times. This has been achieved by utilizing fewer hardware resources, while incurring an average code size increase of 40%.
IEC 61499 has been endorsed as the standard for modelling and implementing distributed industrial... more IEC 61499 has been endorsed as the standard for modelling and implementing distributed industrial-process measurement and control systems. The standard prescribes the use of function blocks for designing systems in a componentoriented approach. The execution model of a basic function block and the manner for event/data connections between blocks are described therein. Unfortunately, the standard does not provide exhaustive specifications for function block execution. Consequently, multiple standard-compliant implementations exhibiting different behaviours are possible. This not only defeats the purpose of having a standard, but makes verification of function block systems difficult. To overcome this, we propose synchronous semantics for function blocks, and show its feasibility by translating function blocks into a subset of Esterel, a wellknown synchronous language. The proposed semantics avoids causal cycles common in Esterel, and is proven to be reactive and deterministic under any composition. Moreover, verification techniques developed for synchronous systems can now be applied to function blocks.
Electronic Notes in Theoretical Computer Science, 2009
We propose a fully pipelined, multithreaded, reactive processor called STARPro for direct executi... more We propose a fully pipelined, multithreaded, reactive processor called STARPro for direct execution of Esterel. STARPro provides native support for Esterel threads and their scheduling. In addition, it also natively supports Esterel's preemption constructs, instructions for signal manipulation, and a notion of logical ticks for synchronous execution. As a side effect of the proposed architecture, we have developed a new intermediate format called UCCFGs d (unrolled concurrent control-flow graph with surface and depth) that closely resembles the Esterel source. A compiler based on UCCFGs d , has been developed for code generation. We have synthesized STARPro and have carried out a range of benchmarking experiments. Experimental results reveal substantial improvement in performance and code size compared to software compilers. We also excel in comparison to recent reactive architectures, by achieving an average speed-up of 37% in worst-case reaction times, and a speed-up of 38% in average-case reaction times. This has been achieved by utilizing fewer hardware resources, while incurring an average code size increase of 40%.
2009 IEEE International Conference on Industrial Technology, 2009
Current trends in the manufacturing sector have greatly increased the need for portability and re... more Current trends in the manufacturing sector have greatly increased the need for portability and reusability in software systems for industrial control and automation. The IEC 61499 standard has emerged out of this need for a platformindependent way to develop industrial control systems. So far, typical IEC 61499 solutions have relied on some run-time environment that differ in the execution model for each implementation. This has resulted in code that is neither portable, nor efficient in terms of execution speed and memory footprint. Therefore, we present, instead, a synchronous model for function blocks, which removes the need for a run-time environment by making all event scheduling decisions during compile-time. This approach has been used to create a function block compiler, with two different back-end code generators. We present experimental results of a benchmark suite implemented using different code generators for different execution models, and show that our technique yields significant gains in efficiency over existing approaches.
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