Abstract: An optoelectronic coupler includes two photodiodes and an optic light guide, where one of the two photodiodes serves as the transmitting diode and the other as the receiving diode and the light guide serves to guide the light emitted by the transmitting diode to the receiving diode. The transmitting diode and the receiving diode are mounted on a circuit board at a distance from each other and the light guide is constituted of a plastic or glass element mounted on the same circuit board. This arrangement provides for a simple optoelectronic coupler design that permits safe operation even from the perspective of explosion protection.

Abstract: A method that rapidly reconfigures a computer network having a plurality of devices executing the spanning tree algorithm. First, one or more devices are configured and arranged so that one port, providing connectivity to the root, is in the forwarding state and the remaining ports, providing connectivity to the root, are in the blocked state. Next, one or more of the blocked ports are designated as back-up ports. Upon detection of a failure at the active forwarding port, one of the back-up ports immediately transitions from blocked to forwarding, thereby becoming the new active port for the device. Following the transition to a new active port, dummy multicast messages are transmitted, each containing the source address of an entity directly coupled to the affected device or downstream thereof. By examining the dummy multicast messages, other devices in the network learn to use to the new forwarding port of the affected device.

Abstract: A run-time data type extension mechanism describes the kinds of performance information collected within a registry located in a main memory of a computer. The data type extension mechanism comprises a base node of a multi-linked tree data structure having associated therewith a buffer portion for storing the collected performance information and a description portion for describing that information. Writer entities specify the contents of these latter portions, i.e., the collected information and its description, at run time to provide an arrangement for dynamically extending the kinds of information collected at the registry.