Star Micronics DP8340R user manual STX-ETX Mode

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9-3. STX-ETX Mode

The start of the STX-ETX mode should occur with a totally empty print buffer. This can be achieved by sending an ENQ code to the printer and checking the status until the status code indicates an empty buffer. At that point, the STX code is sent by the host computer followed by a data block. While receiving the data block, the printer generates a horizontal parity check character. After the data block is sent, the host computer sends an ENQ which causes the printer to return 2 characters, one would be the normal status character, and the second would be the horizontal parity check character that was generated by the printer while the data block was received.

The host computer checks the status character to determine if any vertical parity errors or other errors occurred during block transmission, and checks the horizontal parity character against a character generated in the host computer while the data was transmitted. If there are no errors, ETX causes the buffer to be printed, but if an error is detected, CAN code clears the buffer and the data is transmitted again. Any control codes transmitted to the printer during the STX- ETX mode will be ignored as control codes, but will be included in the check character. This is done to prevent a control code received in error from causing printing of erroneous data.

STATUS

Parity

Vertical and horizontal parity check is executed in STX-ETX mode.

Framing Error

Framing Error occurs when SPACE signal is detected at STOP Bit time. Framing error or even vertical parity error will be indicated by printing “?”.

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Contents DOT Matrix Printer DP8340R Series Serial Interface Trademark acknowledgments Table of Contents RS-232C Current Loop Setting of the DIP Switches DIP-SW Model Name Notation OutlineUnpacking Unpacking and InstallationInstallation of Paper Holders Installation of Paper Holders and Re-Roll Prevention GuardHandling Notes Installation of Re-Roll PreventionPart Identification and Nomenclature Power Supply UnitPrinter Front View PrinterPart Functional Description Installation of Ink Ribbon Installation of INK Ribbon and PaperRemoval of Ink Ribbon Installation of Ink RibbonFor Roll Paper Paper InsertionReplace the Printer Cover Roll Paper Removal Validation Option InstallationControl Codes ESC F Code ESC @ 1BH 40H Printer initialization ESC P Remarks Character Code List General Specifications Input Output AC 100 240 DC 12.0 V± 5% 47Hz 63 Hz Roll Paper and Print Area External Dimensions Printer Interface Circuit Interface SpecificationsDIP-SW2 Setting of the DIP SwitchesError Condition Alarm Mode Connectors and SignalsInterface Connections Cable Connection Peripheral Unit Drive CircuitPeripheral Drive Circuit Control CodesInterface for Model DP8340RD D-SUB 25 PIN Connector Current Loop RS-232CSetting of the DIP Switches Jumper Setting Setting of JumperRemoval of the Bottom Cover CTS D-Sub 25 Pin Connector Peripheral Unit Drive Circuit Peripheral Drive Circuit DTR Mode 1 Block Machine ErrorPaper Empty ON/X-OFF Mode Parity Framing ErrorSTX-ETX Mode STX-ETX Mode Flow Diagram Character Code List Page International Character Sets When Power is Supplied by the User Other parameters may be determined by user
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