Allen-Bradley Company, LLC

Mark Luboski

Timothy J Murphy

William Edward Floro

Odo J Struger

Alan J Campbell

An inter-processor communication module is inserted into a slot of an equipment rack of the type used to connect I/O modules to system processors in a programmable controller. Using two of the inter-processor communication modules in two respective racks, a supervisory processor is connected to two respective local area processors in a distributed control system. The inter-processor communication module has a serial channel controller that connects to the supervisory processor through a serial I/O port and a serial communication channel to communicate blocks of I/O status data. The serial channel controller is coupled to a backplane controller through a common memory and arbitration circuitry to exchange blocks of I/O status data. The backplane controller, which is also a part of the inter-processor communication module, plugs into the backplane of the rack and exchanges blocks of I/O status data with a local area processor. The two controllers also exchange processor status data to coordinate communications which are initiated by the supervisory processor and the local area processor. Methods of transferring I/O status data between the supervisory processor and the local area processors are also disclosed.

Method and apparatus for linking processors in a hierarchical control

The capacity of programmable controllers with a processor module and I/O modules connected in a single equipment rack is expanded by connecting an I/O expansion module in one of the positions normally occupied by a conventional I/O module. The I/O expansion module communicates with the processor module through the rack backplane and also communicates with other racks of I/O modules and with node I/O modules through a serial data channel. Data for I/O modules on the serial data channel are stored in a bulk storage area in the processor module to expand the effective size of an image table of I/O status data that is maintained by the processor module. The processor module is programmed to operate with a backplane controller in the I/O expansion module to transfer data in or out of the bulk storage area. Besides the backplane controller, the I/O expansion module includes a serial channel controller, a common memory and arbitration circuity which allows the controllers to alternate access to the common memory and to exchange data. The serial channel controller controls multiplexing and demultiplexing of I/O status data with the I/O modules through the serial data channel.

Programmable controller with I/O expansion module located in one of I/O

A method and apparatus for access to a programmable controller at a remote location. A peripheral device with a peripheral processor is connected to a port on an I/O module. Blocks of discrete and block transfer data are transferred to and from a common memory in the I/O module where the data is accessible to a serial communication controller that interfaces the module to a high speed serial data channel. Asynchronous communication is provided between the serial communication controller and the peripheral device using a circular buffer in the common memory. Timing considerations are also disclosed.

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Euclid, OH, United States of America

Mark Luboski