AM3270/TR3271 Reference Manual

Glossary
086705 Tandem Computers Incorporated Glossary–5
RS-232. An industry standard for serial data transmission. It describes pin
assignments (for a 25-pin connector), signal functions, and electrical characteristics.
RS-232C is the current standard.
RTS. Request to send. A signal from the host computer or terminal (DTE) to the
modem (DCE) requesting permission to transmit data. Permission is granted when
the modem turns CTS to ON.
subdevice. Each physical device attached to either a line or a cluster controller is
viewed as a subdevice on the AM3270 line. This would include terminals and
printers. The maximum number of subdevices is determined by the DEVICES
modifier.
SUT. Site Update Tape. Distribution tape containing updated versions of Tandem-
supplied software.
switched line. A line configuration for circuit-switched networks such as a public
telephone network. Also called a dial-up line.
synchronous. A general class of data communications that is the opposite of
asynchronous communications. "Synchronous" means a clock signal, separate from
the data signal, is used to synchronize the receive circuits.
SYSGEN. The system generation program. It is run against a CONFTEXT file that
describes a Guardian 90 system configuration, and then generates a
system-customized version of the Guardian 90 operating system. The SYSGEN
program is usually invoked by INSTALL.
TR3271. Access method connecting a Tandem system to an IBM-compatible host
system by emulating one or more 3721-type cluster controllers and their associated
terminals and printers.
tributary. One of multiple stations controlled by a single, centralized supervisor station
in a multipoint data link.