HP 3000 Manuals HP 3000 Manuals
Appendix B SNA Character String (SCS) Support
SNA IMF supports SNA Character String (SCS) control codes, allowing
certain HP printers to operate as LU.T1 (SCS mode) printers. SNA IMF
also supports the 3270 data stream, so HP printers can also operate as
LU.T3 (3270 mode) printers. Only one mode can be active at a time.
Printers in SCS mode use the EBCDIC characterset and dual case printing.
SCS control codes allow Pass Thru to call the TRAN3270 intrinsic
to emulate the following IBM 3287 printer keys:
* PA1
* PA2
* HOLD PRINT
* ENABLE PRINT
* CANCEL PRINT
These keys are used to communicate with the host application
program to suspend, resume, or cancel print operation.
The SCS data stream has fifty-six control codes. The IBM 3287 printer
supports 18 of the SCS control codes, and HP printers support 17 of those
18 control codes. The Set Attribute (SA)SCS control code is the only
code supported by the IBM 3287 that HP printers do not support. The SA
control code is an extension of the SCS data stream and is considered an
option by IBM. Also considered optional SCS extensions are the Structured
Field and Attribute Processing (SFAP)features. SNA IMF does not support
these options.
Unsupported codes, if received, are rejected with sense code X'1003'
(function not supported).Table B-1 contains a brief description of each
SCS code supported by SNA IMF.
NOTE An LU.T1 session can support only a screen image of 3870 bytes and
an RU size of 3584 bytes. If you exceed this RU limit, the screen
image will be overwritten.
For a complete description of the 17 supported SCS codes, refer to the
IBM 3287 Printer Models 1 and 2 Component Description (IBM P/N
GA26-3153).
SCS control codes and parameters can span request unit (RU) boundaries
within the same RU chain. However, if SCS control codes or parameters
span RU chains, the printer will stop processing SCS parameters and send
a negative response X'1005' (parameter error). Upon receipt of the first
in chain, it will return to SCS data processing.
As with the IBM 3287 printer, you must physically alignpaper forms at the
first line to be printed when you insert forms into the printer. This
action will ensure correct feeding of the forms. Also, any change in
format (SHF, SLD, SVF) must be followed by the appropriate synchronizing
function (CR, NL, FF) in order to maintain format integrity.
Table B-1 describes the SCS control codes as emulated by Pass Thru.
Table B-1. SCS Codes Emulated by Pass Thru
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| |
| SCS Code EBCDIC SCS Name Pass Thru's Action |
| (hex) |
| |
| CR 0D Carriage Return Moves the print position |
| horizontally to the left margin on |
| the same line. If the print |
| position is already at the left |
| margin, then Pass Thru does |
| nothing. |
| |
| LF 25 Line Feed Moves the print position |
| vertically down to the next line. |
| |
| NL 15 New Line Moves the print position |
| horizontally to the left margin |
| and vertically down to the next |
| line. |
| |
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Table B-1. SCS Codes Emulated by Pass Thru (cont.)
--------------------------------------------------------------------------------------------
| |
| SCS Code EBCDIC SCS Name Pass Thru's Action |
| (hex) |
| |
| BS 16 Back Space Moves the print position |
| horizontally one position to the |
| left without regard to the left |
| margin. If the print position is |
| already at column one, then Pass |
| Thru does nothing. |
| |
| FF 0C Form Feed Moves the print position to the |
| top left margin of the next form. |
| If the maximum print position has |
| not been set, a default value of |
| one is used, and the print |
| position moves to the left margin |
| of the next line. |
| |
| HT 05 Horizontal Tab Moves the print position |
| horizontally, from left to right, |
| to the next tab stop. A space is |
| printed if there are no horizontal |
| tab stops set to the right of the |
| current print position. If the |
| maximum print position has been |
| passed, a New Line is performed. |
| |
| VT 0B Vertical Tab Moves the print position |
| vertically down to the next |
| vertical tab stop. A line feed is |
| printed if there are no vertical |
| tab stops below the current print |
| position. If the bottom margin |
| has been passed, a Form Feed is |
| performed. |
| |
| SHF 2BC1 Set Sets the maximum print position, |
| HorizontalFormat left margin, right margin, and |
| horizontal tab stops. The format |
| of the parameters and the defaults |
| are the same as those specified in |
| the IBM 3287 Printer Models 1 and |
| 2 Component Description. |
| |
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Table B-1. SCS Codes Emulated by Pass Thru (cont.)
--------------------------------------------------------------------------------------------
| |
| SCS Code EBCDIC SCS Name Pass Thru's Action |
| (hex) |
| |
| SVF 2BC2 Set Sets the maximum print line, top |
| VerticalFormat margin, bottom margin, and |
| vertical tab stops. The format of |
| the parameters and defaults are |
| the same as those specified in the |
| IBM 3287 Printer Models 1 and 2 |
| Component Description. |
| |
| SLD 2BC6 Set Line Density The emulator accepts this code, |
| but performs no function. The |
| default density of 6 LPI is always |
| used. An IBM 3287 allows |
| densities of 3, 4, 6, or 8 LPI. |
| |
| VCS 04 nn Vertical Causes a Line Feed to be |
| ChannelSelect performed. This is the same |
| operation an IBM 3287 performs. |
| The IBM 3287 does not support |
| skipping using the VCS code. |
| |
| TRN 35 Transparent Provides for transmitting data in |
| transparent mode. Transparent |
| data is not checked for SCS codes. |
| The print position moves one |
| character position as each data |
| byte is interpreted. Valid |
| graphics are printed and invalid |
| graphics are printed as hyphens |
| (-). (Invalid graphics are |
| identified by hyphens in figure |
| A-11 of the IBM 3287 Printer |
| Models 1 and 2 Component |
| Description.) |
| |
| Note that the first byte following |
| the TRN code is a binary value |
| defining the number of bytes of |
| transparent data to follow. This |
| length does not include the length |
| byte. |
| |
| IRS 1E InterchangeRecord Causes a New Line to be performed. |
| Separator This response is identical to the |
| response of an IBM 3287 printer. |
| |
| BEL 2F Bell The emulator accepts this code but |
| performs no function. An IBM 3287 |
| rings the bell. |
| |
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Table B-1. SCS Codes Emulated by Pass Thru (cont.)
--------------------------------------------------------------------------------------------
| |
| SCS Code EBCDIC SCS Name Pass Thru's Action |
| (hex) |
| |
| INP 24 Inhibit The emulator accepts this code, |
| Presentation but performs no function. This |
| response is identical to the |
| response of an IBM 3287 printer. |
| |
| ENP 14 Enable The emulator accepts this code, |
| Presentation but performs no function. This |
| response is identical to the |
| response of an IBM 3287 printer. |
| |
| GE 08 nn Graphics Escape Causes a hyphen to be printed for |
| the graphics escape character. |
| The character that follows the |
| graphics escape character is |
| printed using the base character |
| set. This is identical to what |
| the IBM 3287 does when the APL |
| Text feature is not installed. |
| |
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