Rockwell Automation Technologies Incorporated

Alex Harris

Suresh Ramanujan Nair

Rudolf Papenbreer

Wayne R Foster

Norbert Machuletz

Oliver Heckel

Thomas Helpenstein

Van Duros

Dirk Lorenz

Christopher Burke

Rudolf Laurenz Papenbreer

Rudolf Lorenz Papenbreer

A single-wire safety system is provided that yields reliable safety device monitoring without the need for dual redundant signal channels. The safety system comprises a safety relay acting as a communications master device and one or more safety devices connected in series with the safety relay via a single-wire communication circuit. A smart tap device is used to interface safety devices that are not compliant with the single-wire protocol to the single-wire channel. The safety device or smart tap device farthest from the safety relay on the safety circuit modulates a safety signal with a recognizable pulse pattern that traverses the single-wire safety circuit to the safety relay via the intermediate safety devices or smart taps. The safety relay maintains safety mode as long as the pulse pattern is received and recognized. The architecture allows bi-directional communication of initialization, configuration, and diagnostic messages over the single-wire safety channel.

Smart taps for a single-wire industrial safety system

A single-wire safety system architecture is provided that yields reliable safety device monitoring without the need for dual redundant signal channels. The safety system comprises a safety relay acting as a communications master device and one or more compatible safety devices connected in series with the safety relay via a single-wire communication circuit. The safety device farthest from the safety relay on the safety circuit modulates a safety signal with a recognizable pulse pattern that traverses the single-wire safety circuit to the safety relay via the intermediate safety devices. The safety relay maintains safety mode as long as the pulse pattern is received and recognized. The architecture allows bi-directional communication of initialization, configuration, and diagnostic messages over the single-wire safety channel, and can also allow safety devices to insert prognostic data into the safety signal in order to convey health information while the system is in normal operation mode.

Single-wire industrial safety system with safety device diagnostic communication

A single-wire safety system architecture is provided that yields reliable safety device monitoring without the need for dual redundant signal channels. The safety system comprises a safety relay acting as a communications master device and one or more compatible safety input devices connected in series with the safety relay via a single-wire communication circuit. The safety input device farthest from the safety relay on the safety circuit modulates a safety signal with a recognizable pulse pattern that traverses the single-wire safety circuit to the safety relay via the intermediate safety devices. The safety relay maintains safety mode as long as the pulse pattern is received and recognized. In addition to conveying the safety signal, the architecture allows bi-directional communication of initialization, configuration, and diagnostic messages over the single-wire safety channel. The architecture also facilitates rapid initialization of the safety channel using asynchronous sub-link detection and device enumeration.

Diagnostics and enhanced functionality for single-wire safety communication

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Salem, MA, United States of America

Alex Harris