Agilent Technologies 5250 user manual Appendix C Pseudo Transparency, Data Pseudo Transparency

APPENDIX C — PSEUDO TRANSPARENCY Page C-1

APPENDIX C

PSEUDO TRANSPARENCY

Introduction

Most ASCII and EBCDIC printers have features that are not available on IBM midrange printers. If the user’s application software is aware that the destination of the data may be a non-IBM printer attached to a protocol converter, the application can send printer commands that will activate the printer’s advanced features.

Printer commands must be sent to the printer without being modified by the System or the protocol converter. For this to occur, the commands must be sent in a transparent packet. (Refer to the printer user’s manual for a list of available printer commands.)

A transparent packet consists of a trigger followed by the data or command that will be sent to the printer. The trigger alerts the protocol converter that the data that follows it should be sent directly to the printer without translation.

The 5250 OPTIMA will recognize the triggers for IBM transparency (35h), ASCII transparency (03h) in IBM emulation mode, Xerox Metacode transparency (35h) in IBM emulation mode, and Xerox transparency (36h) in Xerox 275 twinax protocol converter emulation mode. The 5250 OPTIMA will also support two forms of pseudo transparency.

i-data Pseudo Transparency

This form of pseudo transparency is valid only for twinax data streams when the 5250 OPTIMA is in IBM emulation mode.

The trigger used by i-data applications for pseudo transparency is designated by the user within the application. The application sets the trigger at the protocol converter by sending two ampersand characters (&&), two question marks (??) and the designated transparency trigger. For instance, to define the trigger as a percent sign (%), the application would send the following command string:

& & ? ? %