Allen-bradley Company, LLC

Gerald S Pepera

Kerry Van De Steeg

Steven P Blech

Richard S Gunsaulus

Edwin L Bremenour

Michael F Tratar

James E Schey

Gene S Laurich

A structural key is checked under program control to control the mode of operation for a processor-based electronic circuit board. A break-away key portion of the circuit board is connected to the main portion along a boundary of frangible links with circuit paths traversing the boundary and carrying logic signals. The presence or absence of the break-away portion is sensed by sensing the bit pattern at an I/O address. If the absence of the break-away portion is sensed, the function of a user-commanded motion block is tested and processor operation is limited to executing functions for the mode corresponding to the absence of the break-away portion.

Break-away key for electronic circuitry

An industrial controller Input/Output module includes on-board processing circuitry in the form of a microprocessor and associated memory, a first programmable logic circuit and a second programmable logic circuit connected through an isolation interface. The isolation interface is comprised of optical coupling circuits. The programmable logic circuits are programmed to provide circuitry for parallel-to-serial data conversion of 24 bits of system Input/Output data on each side of the isolation interface. The data is then transferred as serial data in both directions at once in response to a shift clock signal. The data signals and the shift clock signal utilize three one-bit optical coupling devices in the isolation interface. After transfer across the isolation interface, the system Input/Output data is converted to parallel data for further processing.

Method for synchronously transferring serial data to and from an

A method and a circuit limit access to a locked portion of memory to periods when application program instructions in the locked portion of memory are being executed. An UNLOCK routine of processor instructions is executed before accessing the portion of the memory storing the application program instructions and a LOCK routine of processor instructions is executed to re-secure the memory after such access. The locking and unlocking is accomplished by addressing a comparator and transmitting data representing either a lock value or an unlock value. The comparator is connected to enable and disable decoding circuitry which in turn controls access to the locked portion of memory.

Method and circuit for limiting access to a RAM program memory

A memory cartridge for convenient manual attachment of a RAM memory with battery back-up to an I/O module in a programmable controller system is inserted through an opening in a side cover of the I/O module and connected to a main circuit board. The housing has a pair of clip members on opposite ends with grooves running transversely across the ends to receive the edges of mounting flanges extending inward at upper and lower ends of an opening in the side cover. The clip members are yieldable in the longitudinal direction of the cartridge housing--to squeezed between a thumb and fingers of one hand--and when the cartridge is inserted through the side cover opening to a certain depth, the clip members are released to secure the cartridge between the mounting flanges.

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Mentor, OH, United States of America

Gerald S Pepera