Summary Of Physical And Logical Unit Types; Physical Unit Types And Examples; Logical Unit Types And Typical Ibm Products - IBM 6400 Programmer's Reference Manual

Installation and Configuration
Review "Configuring IPDS from the Printer Operator Panel" on page 17 and the
6400 Setup Guide, S246-0116 for information on setting printer configuration
values.

Summary of Physical and Logical Unit Types

This section provides a brief description of some commonly used Physical Unit
(PU) types and Logical Unit (LU) types that you need to understand when
configuring your printer on your host system.
The PU defines the type of communications relationship that the HOST VTAM
has with a communications controller such as a 3174 control unit or a controller
inside a printer such as a 3820 or 3935. Alternatively, it can describe the
relationship that one host VTAM has to another host VTAM or equivalent such as
AS/400.

Physical Unit Types and Examples

Physical Units (PU) are tied to physical hardware such as a control unit (3174,
3274). VTAM and NCP use various PU types in conjunction with the Logical Unit
(LU) types to define the device and logical session to be established with an SNA
network.
PU type 2: The PU type 2 is the physical unit type that is required for an LU type
0, type 1, or type 3 (see LU type description following). Examples of PU type 2
are 3174 or 3274 control units.
PU type 2.1: The PU type 2.1 is the physical unit type that is required for an LU
6.2 Examples of PU type 2.1 is an IBM 3820, IBM 3935, or PSF/2.

Logical Unit Types and Typical IBM Products

Listed below are the LU types that SNA currently defines and the kind of
configuration or application that each type represents. Also mentioned are
hardware or software products that typically use each type of logical unit. A
logical unit (LU) describes the type of relationship that the Host VTAM and
applications have with a specific device such as a printer. This relationship
determines the commands supported from the host to the device and the type of
feedback the device gives to the host.
LU type 0: LU type 0 printers are Non-SNA Local or Bisync connections. This
mode is also commonly called DSC (Data Stream Compatibility) mode printing.
An example of an LU 0 printer connection is an IBM 3816 attached to a non-SNA
3274 or 3174 control unit. Not all printers support this type connection. This
connection type is used when VTAM is controlling the non-SNA control unit and
device.
LU type 1: An LU type 1 is for an application program that communicates with
single or multiple-device data processing workstations in an interactive, batch
data transfer, or distributed data processing environment. The data stream
conforms to the SNA Character String (SCS) or Document Content Architecture
(DCA). An examples of a printer that is able to communicate via LU1 are 4230,
4234, 3930, 6400 and others.
16
6400 IPDS
Emulation Configuration => IPDS => Check Graphic Quality, Bar Code
•
Quality, and Graphics Quality settings for desired quality.