Browse Prior Art Database

Customer Controlled Priority and Select Propagation. June 1982

IP.com Disclosure Number: IPCOM000049555D
Original Publication Date: 1982-Jun-01
Included in the Prior Art Database: 2005-Feb-09
Document File: 2 page(s) / 57K

Publishing Venue

IBM

Related People

Spencer, JW: AUTHOR [+2]

Abstract

Appropriate bypass and driver/receiver functions are selectable by a customer actuated DPST (double pole, single throw) switch 10 provided in the receive/bypass circuit of each subsystem connected in a loop to a central processor in a receive retransmit type polling system.

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Customer Controlled Priority and Select Propagation. June 1982

Appropriate bypass and driver/receiver functions are selectable by a customer actuated DPST (double pole, single throw) switch 10 provided in the receive/bypass circuit of each subsystem connected in a loop to a central processor in a receive retransmit type polling system.

Polling systems in general are described, for example, in U.S. Patent 4,224,684. In a receive retransmit system, the polling signal is transmitted from one subsystem to the next in a predetermined priority sequence through a terminal device in the subsystem. Thus, if a particular terminal device does not require service at the time the polling signal is received, that device retransmits the polling signal to the next lower-order priority subsystem in the loop. The cycle continues until the first subsystem requiring service captures the polling signal. The receive/bypass circuit included in each subsystem is capable of routing a polling signal to a powered terminal device in service in the particular subsystem or past an out of service device whether powered or unpowered.

In the high priority mode for the particular terminal device, switch 10 of the present system is closed on contacts Hi and the Power On Reset (POR) pole 10A of switch 10 is connected to control logic 11. This allows the timing sequence outputs A, B, C of logic 11 to gate the driver 12 for the SELECT OUT line 13, to gate and terminate the receiver. RECEIVER NO. 1, f...