AM3270/TR3271 Reference Manual

Bisync Procedures
Bisync Protocols—Concepts and Terminology
1–12 086705 Tandem Computers Incorporated
The cluster controller manages the link between the supervisory station and the
tributaries on that line, which reduces response time from the network. The cluster
controller handles all of the messages to and from the stations on its link. As a result,
the supervisory station (or CPU, or front-end processor) needs to poll only each cluster
controller, and not each of the individual stations attached to it.
The front-end processors manage the link between the supervisory station or CPU and
the cluster controller, which reduces the time demands on the supervisory station or
CPU. The front-end processor handles all of the polling and selecting activity, which
frees the supervisory station or CPU from much of the communications processing.
Tandem’s 6100 family controllers handle these tasks, and as such, are similar to front-
end processors.