A functional safety switch output module with high diagnostic coverage

Abstract

The invention relates to a functionally safe switching value output module with high diagnostic coverage, wherein the switching value output unit is connected to a microprocessor, and the digital signal transmitted from the microprocessor is converted into a switching value signal for output; one end of the diagnosis unit is connected to the switching value output unit , to collect the switching signal of the switching output unit; the other end is connected to the microprocessor, and the collected switching signal is fed back to the microprocessor; the diagnosis unit receives the control signal and configuration signal sent by the microprocessor; the switching output unit and The diagnostic units together form a 1001D voting structure. The switch of the diagnostic unit and the switch of the digital output unit are connected in series. When a fault occurs, the microprocessor controls the switch of the diagnostic unit to be disconnected, so that the power input is turned off. The invention adopts a DAC with rich self-diagnostic functions combined with a diagnostic unit, an output monitoring unit, and a voltage monitoring unit, which further improves the diagnostic coverage, improves reliability, reduces cost, and reduces development difficulty.

Description

technical field

[0001] The invention relates to the fields of switching output and automatic process control with functional safety requirements, in particular to a functionally safe switching output module with high diagnostic coverage. Background technique

[0002] With the rapid development of modern industry, the control scale of industrial production process is constantly expanding, the complexity is constantly increasing, the process is constantly strengthening, and the safety requirements for control systems are also getting higher and higher. In the production process, the safety PLC used to monitor the production process and take corresponding measures to prevent dangerous events under dangerous conditions has gradually been applied.

[0003] Functional safety switch output module is a commonly used IO module in safety PLC. The traditional switch output module with SIL3 safety level adopts one of the 1002D or 2003 architectures. The design complexity of these two ar...

Examples

Embodiment Construction

[0026] The present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments.

[0027] Such as figure 1 Shown is the block diagram of the module structure of the present invention.

[0028] A functional safety switching output module with high diagnostic coverage communicates with a safety controller through a PLC backplane bus interface to realize control of field devices. The switch output module is mainly composed of a microprocessor, a communication interface, an address detection unit, a switch output unit, a diagnosis unit, an external power monitoring unit, and an isolation circuit.

[0029] The communication interface adopts a redundant structure to communicate with the PLC controller through the PLC backplane bus; the address detection unit adopts a redundant structure and is responsible for detecting the address of the module; the switch output unit passes through the isolation unit before and after and the mic...

technical field

[0001] The invention relates to the fields of switching output and automatic process control with functional safety requirements, in particular to a functionally safe switching output module with high diagnostic coverage. Background technique

[0002] With the rapid development of modern industry, the control scale of industrial production process is constantly expanding, the complexity is constantly increasing, the process is constantly strengthening, and the safety requirements for control systems are also getting higher and higher. In the production process, the safety PLC used to monitor the production process and take corresponding measures to prevent dangerous events under dangerous conditions has gradually been applied.

[0003] Functional safety switch output module is a commonly used IO module in safety PLC. The traditional switch output module with SIL3 safety level adopts one of the 1002D or 2003 architectures. The design complexity of these two ar...

Examples

Embodiment Construction

[0026] The present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments.

[0027] Such as figure 1 Shown is the block diagram of the module structure of the present invention.

[0028] A functional safety switching output module with high diagnostic coverage communicates with a safety controller through a PLC backplane bus interface to realize control of field devices. The switch output module is mainly composed of a microprocessor, a communication interface, an address detection unit, a switch output unit, a diagnosis unit, an external power monitoring unit, and an isolation circuit.

[0029] The communication interface adopts a redundant structure to communicate with the PLC controller through the PLC backplane bus; the address detection unit adopts a redundant structure and is responsible for detecting the address of the module; the switch output unit passes through the isolation unit before and after and the mic...

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