Serial Link Communication Module for Local Work Station Attachments
Original Publication Date: 1983-Nov-01
Included in the Prior Art Database: 2005-Feb-07
This article describes a Serial Link Communication Module (SLM) with a number of modes that are used to select the level of link protocol and error recovery appropriate to primary stations, protocol interactive secondary stations and protocol transparent secondary stations. See Figs. 1 and 2. In the primary station use, the SLM 10 provides hardware assist to the primary microprocessor 12, consisting of auto poll from command list, SDLC (synchronous data link control) address generation and checking, frame count generation and checking, and idle detect time out. A variable number of devices can be polled under auto poll, and the auto poll can be terminated by either SLM 10 or microprocessor 12. The idle detect time out in SLM 10 provides for automatic retry of a frame transmission.