Abstract: A repeater for use in a data communications link, particularly of the type to provide the exchange of process control information with external controlled equipment, includes a detector for detecting incoming data presented on the data communications link. Through the use of a free running internal clock, the data is retimed, reconstructed through the use of a modulator and presented to a transmitter for placement back on the data link. The repeater further provides data and clock signals to the external controlled equipment and receives signals from that equipment which serve, by way of logic circuitry within the repeater, to effect the modification of the data received by the repeater to thus enable the controlled equipment to communicate with other elements connected to the link.

Abstract: A waveguide opening for moving paper in and/or out of a data printer employing wave attenuators and reflectors to suppress electromagnetic wave radiation generated within said printer from escaping through the paper opening.