[ Previous | Next | Contents | Search ]
3270 Host Connection Program 2.1 and 1.3.3 for AIX: Guide and Reference

HCON Printer Emulation

HCON supports continuous printing of printer data streams from the host. The data streams consist of characters, highlights, and formatting commands interpreted and translated into characters and controls specific to the locally configured printer. Two data stream types are supported: SNA Character String (SCS) and 3270.

Concurrent printer sessions are supported. For example, a print server in a cross-network environment can initiate a print job from a host within a network and route the print job to a different host on the same or a different network.

HCON printer sessions are supported in these environments:

Local systems emulate 3287 model 1 and 2 printers. The following print characteristics are not supported:

Starting and Controlling a Printer Session

A printer session is defined both on System/370 hosts and on the local operating system. The host definition for display or printer sessions must match in terms of resource definition and the type of print data stream. From the local system, you can:

3270 Data Stream Support for Printer Sessions

Printer emulation supports two types of host-directed printer data streams: the 3270 printer data stream and SCS. These two types are capable of producing similar output, in different ways.

3270 Printer Data Stream

The 3270 printer data stream is used in non-SNA DFT configuration, as well as in the SNA Standalone LU3 environment.

The 3270 printer data stream is a buffer-oriented data stream, similar to the 3270 display data stream processed by the HCON program. This data stream is sent using the non-SNA DFT or SNA LU type 3 interface as session data. The following codes are included in a 3270 printer data stream. They are valid only when bits 2 and 3 of the Write Control Character (WCC) in the data stream are set to B'00'.

NL (New Line) Moves the print position horizontally to the left margin and vertically down to the next line.
CR (Carriage Return) Moves the print position horizontally to the left margin.
EM (End of Message) Terminates the print operation.
FF (Form Feed) Moves the print position to the top and left margin of the next page.
Note: For a complete list of 3270 codes, see the 3270 Information Display System Data Stream Programmer's Reference.

SCS Printer Data Stream

The SCS printer data stream is a sequential data stream specifically oriented toward line printers. The data stream consists of characters and commands. The characters are printed according to the attributes and formatting information specified by the control commands. How each SCS character is printed depends on the control commands that precede it. Optionally, the data stream can be transported using an SNA Function Management Header (FM Header) of type 1, supported by an LU type 1 session.

The SCS codes supported by HCON in a DBCS environment include:

Supported SCS Control Codes for DBCS
Symbol Hex Value Command
SA 28 Set Attribute (character set and field outlining)
SO 0E Shift Out
SI 0F Shift In

The SCS codes supported include:

Supported SCS Control Codes
Symbol Hex Value Command
BS 16 Backspace
BEL 2F * Bell
CR 0D Carriage Return
FF 0C Form Feed
HT 05 Horizontal Tab
IRS 1E Interchange Record Separator
LF 25 Line Feed
NL 15 New Line
NUL 00 Null
PP 34 * Presentation Position
PPM 2BD2XX48 * Page Presentation Media
SA 28 Set Attribute (supports Highlight attribute of type Underline only)
SHF 2BC1 Set Horizontal Format
SLD 2BC6 Set Line Density
SPD 2BD229 Set Print Density
SVF 2BC2 Set Vertical Format
TRN 35 * Transparent
VT 0B Vertical Tab
Notes:    1. The * (asterisk) indicates the codes ignored in a DBCS environment.
   2. The program ignores all other SCS codes.

SCS Structured Fields

The SCS structured field is a format used to transport SCS data. Outbound structured fields are data fields sent from the host to the local system running HCON. Inbound structured fields are sent from the local system to the host system.

Outbound Structured Fields

Outbound SCS data is transported as raw data or packaged in one or more SCS structured fields preceded by a type 1 FM Header. The FM Header indicator is part of the SNA Request/Response Header. The FM Header type 1 structure includes:

FM Header Type 1 for Outbound and Inbound Structured Fields
Byte Value Description
0 X'06' Length of Header
1 X'01' FM Header type 1
2 X'00' Reserved
3 X'0B' X'8B' Outbound Structure Fields included with this FM Header Inbound Structure Fields included with this FM Header
4 X'60' No compressed data
5 X'00' Always 00

If an FM Header is specified in the BIND time (handshaking period), HCON expects the outbound SCS data in structured field format. If FM Header support is indicated in the bind and raw data follows, PROG756 displays in the Operator Information Area (OIA) of the LU 1 printer session.

HCON supports these outbound structured fields:

Inbound Structured Fields

The FM Header is optionally used by the printer session to transmit the inbound data. FM Header support is determined during the session bind time. For a printer session, the only inbound data is a reply to a Read Partition (Query)  function.

The supported inbound structured field in response to a Read Partition (Query) function includes these substructures:

Usable Area Specifies the print buffer size and location.
Character Sets Identifies the supported character set.
Colors Identifies the supported colors.
Highlighting Specifies the supported highlighting types.
Field Outlining Specifies the details of field outlining for DBCS support only.

[ Previous | Next | Contents | Search ]