Control system with error detection
OwnerDavid Mielnik, Thomas Heilman +1inventors
InventorsDavid Mielnik, Thomas Heilman, John Piunno
Life of this patent
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Abstract
A control system for controlling a process. The control system includes primary and secondary module buses over which information may be transmitted between a controller and a plurality of I/O modules. Each of the controller and I/O modules has a power sense circuit for detecting current on the high side of a driver and a ground sense circuit for detecting current on the low side of the driver. The driver is determined to have failed if either the current on the high side of the driver measured by the power sense circuit is outside a predetermined high range or the current on the low side of the driver measured by the ground sense circuit is outside a predetermined low range.
Claims20
A control system for controlling a process, the control system comprising:
- a module bus over which information may be transmitted;
- a controller module connected to communicate over the module bus, the controller module being programmed to perform operations for controlling the process using data transmitted over the module bus;
- a plurality of I/O modules connected to communicate with the controller module over the module bus, each I/O module including:
- a microprocessor with memory;
- a driver for sending information to the module bus and having a high side connected to a voltage source and a low side connected to ground;
- and
- a sense circuit for detecting current on the high side of the driver;
- and
- wherein the microprocessor is operable to execute computer-executable instructions stored in the memory to perform an I/O module error detection method that comprises determining whether the current on the high side of the driver measured by the sense circuit is outside of a predetermined high range and, if so, determining that the driver has failed.
A control system for controlling a process, the control system comprising:
- first and second module buses over which information may be transmitted;
- a controller module connected to communicate over the first and second module buses, the controller module being programmed to perform operations for controlling the process using data transmitted over one or more of the first and second module buses;
- and
- a plurality of I/O modules connected to communicate with the controller module over the first and second module buses;
- wherein the controller module and each of the I/O modules comprise:
- a microprocessor with memory;
- a driver for sending information to the first module bus and having a high side connected to a voltage source and a low side connected to ground;
- and
- a power sense circuit for detecting current on the high side of the driver;
- a ground sense circuit for detecting current on the low side of the driver;
- and
- wherein the microprocessor is operable to execute computer-executable instructions stored in the memory to perform a module error detection method that comprises:
- determining whether a communication error has occurred on the first module bus;
- if a communication error has occurred on the first module bus, determining whether the current on the high side of the driver measured by the power sense circuit is outside a predetermined high range and whether the current on the low side of the driver measured by the ground sense circuit is outside a predetermined low range;
- and
- if either the current on the high side of the driver is determined to be outside the predetermined high range or the current on the low side of the driver is determined to be outside the predetermined low range, determining that the driver has failed.
A method of detecting errors in a process control system having a plurality of modules connected to communicate over first and second module buses, each module having a driver for sending information to the first module bus and having a high side connected to a voltage source and a low side connected to ground, the method comprising:
- determining in each of the modules whether a communication error has occurred on the first module bus;
- measuring the current on the high side of the driver in each of the modules where a communication error has been determined to have occurred;
- measuring the current on the low side of the driver in each of the modules where a communication error has been determined to have occurred;
- comparing the measured current on the high side of the driver in each of the modules where a high side measurement has been made to a predetermined high range;
- comparing the measured current on the low side of the driver in each of the modules where a low side measurement has been made to a predetermined low range;
- and
- determining that the driver in one of the modules has failed if either the current on the high side of the driver is outside the predetermined high range or the current on the low side of the driver is outside the predetermined low range.
Dependencies are inferred from the claim text.