AM3270/TR3271 Reference Manual

For More Information
Bisync Protocols—Concepts and Terminology
1–14 086705 Tandem Computers Incorporated
are not interpreted as control sequences such as “end-of-transmission.” However,
even during transparent operation, some form of line control is still required.
When transparent mode is turned on, any subsequent control characters are
interpreted as raw data only. Characters that are meant to be interpreted as control
characters are preceded by a data link escape (DLE) character. When an existing DLE
character is imbedded in the text, a second DLE is inserted, so that the following
character is not mistaken for a control character.
The receiving station identifies the control character by looking for DLEs, which it
strips before interpreting the control character. If the control character turns out to be
another DLE, then it is interpreted as data.
For More Information The remaining sections of this manual discuss Tandem’s implementation of the bisync
protocols in its AM3270 and TR3271 access methods. In addition, you may find the
following manuals helpful.
Tandem manuals:
Introduction to Tandem Networking and Data Communication
An overview of Tandem’s networking capabilities and data communications
protocols.
IBM manuals:
General Information—Binary Synchronous Communications, IBM Publication No.
GA27-3004, IBM Systems Development Division, Publications Center.
An introduction to IBM’s BSC protocol.
General Information—I BM Synchronous Data Link Control, IBM Publication No.
GA27-3093, IBM Systems Development Division, Publications Center.
An introduction to IBM’s SDLC protocol.
I BM 3270 Information Display System—3274 Control Unit Description and
Programmer’s Guide, IBM Publication No. GA23-0061-2, IBM Systems Development
Division, Publications Center.
3174 Establishment Controller, Functional Description, IBM Publication No.
GA23-0218, IBM Systems Development Division, Publications Center.
Specifics about the bisync data stream, and details on the 3174 controller.
General reference manuals (useful introductions to data communications):
Technical Aspects of Data Communication, John E. McNamara, Digital Press
(Digital Equipment Corp.), 1988.
Principles of Data Communication, James Martin, Prentice Hall, 1988.