101, Errors, Data Flow Control | Lexmark 248X, 249X instruction

When No parity is selected, the pritner expects no parity bit when it receives data. The printer transmits data without parity bits.

When Ignore parity is selected, the printer expects a parity bit when it receives a data frame. Although the printer expects a parity bit, it ignores the bit and does not check for a parity error condition. The printer uses even parity when it transmits data.

Errors

The serial interface recognizes the following three error conditions: Parity Error, Framing Error, and Buffer Overrun.

When a parity error is detected, the interface prints an upside down question mark. Although the printer continues to receive data, it prints an upside down question mark for each byte that has a parity error.

A framing error is similar to a parity error. When a framing error is detected, the interface also prints an upside down question mark and continues to receive data. However, unlike a parity error which causes the interface to print question marks only for the bytes with incorrect parity, a framing error causes the interface to print question marks for all bytes transmitted.

A buffer overrun error occurs when the host does not obey the selected protocol and continues to send data even after the buffer is full. The buffer can only hold 128 bytes of data after the printer signals that it is busy. If the host sends more than this amount, the data is lost and a buffer overrun error occurs.

Data Flow Control

Flow control is accomplished by way of software or the hardware DTR (Data Terminal Ready). Three flow control protocols are available:

•DTR Pacing (hardware)

•XON/XOFF (software)

•Multi XON/XOFF (software)

DTR Protocol Timing

You use DTR to control the data flow from the computer. DTR goes from high to low to indicate to the computer that the printer cannot receive more data due to one of the following conditions:

•Buffer full

•Attendance error (paper out, printer error)

•Printer not in ready state

Section 6: Using the Printer Interface	101

Image 101

Lexmark 248X, 249X manual 101, Errors, Data Flow Control

Contents

Forms Printer 248x/249x United States Government Restricted Rights Contents Page Epson Mode Printer Commands Barcodes Glossary Index Viii Introduction Width Height Depth Weight Physical CharacteristicsAvailable Options Options Part Number 2480 2481 2490 2491 Print Speeds Mode 2480/2481 2490/2491Printhead Description 248x Environmental Conditions Power Requirements Power Cord Alternating Current Line Voltage PowerNoise Emission Value Following are noise emission values for your printer Length Paper Specifications2480/2490 Narrow Carriage Models 2481/2491 Wide Carriage Models Manual Feed cut sheets Tractor Feeder continuous forms Diagnostics Ribbon SpecificationsPower-On Diagnostics Printer Test Programming Examples Wend Introduction Use the following format SIC Command Format Initial Values Description Bit Off Printer Dec HexParm Description Selection Dec Hex Parm Description Selection Dec Hex Parm Description Selection Dec Hex Parm Description Selection Dec Hex Control Codes Code Symbol Description Value Name Dec Hex Escape Sequences Printer Command Parameters Command Structure Select Code Page name of command Example of IBM Emulation Mode Printer Command Function Command Dec Hex See Printer Command Quick Reference IBM Emulation ModeFor more Information Mode data Data 1B 5B 67 Ln Hn mode58 n1,n2 M3 m4 Select Code Selecting a Character SetSelect Character Set Usage Notes Continuously Print Characters from a Code Print From Code Print One Character Download a Character SetUsage Note Located in the code page tables beginning on Start low/start high Select Global Font Prestige Select Global FontGothic Script PresentorOrator Global Font and Code Global Font and Size ParametersPitch Dec Hs, Ls Hex Hs, Ls Code Decimal Hex Select 12 cpi Select Print ModeThis command sets the pitch at 12 cpi 249x Dec Hex Print Mode248x Select Print Type Style Height Line Space Dec Hex Dec Hex Emphasized Bold Print Use this command for bold print To begin bold printDouble-Strike Print To end bold print Set Print Direction Superscript or Subscript Sets double-wide printing mode Cancels double-wide printing modeContinuous Double-wide Printing Score Select Continuous Overscore Continuous Underline Decimal Hex Set Print Quality Normal Density Bit Image Graphics Bit Number Binary Value Print WiresGraphics Print Modes Horizontal Density Wires Mode and Horizontal Density 249x OnlyMode Dec Dual-Density Bit Image Graphics Half Speed Mode Dec Hex Horizontal Density Wires High-Density Bit Image Graphics Dual-Density Bit Image Graphics Normal Speed Set Horizontal Tabulation Stops Set Default Tabulation StopsHorizontal Movement Move Current Print Position This command sets the left and right marginsSet Horizontal Margins Automatic Line Feed LF Line ControlReverse Line Feed Move Paper Vertically Set Vertical Units Vertical TabulationSet Vertical Tabulation Stops Sets as many as 64 tabulation stops by line number Set Line Spacing to 1/8 Inch Line SpacingSet Line Spacing to 7/72 Inch Activate Line Spacing for Text This command turns porportional space mode on and off Porportional Space ModeSet Line Spacing for Text Set Line Spacing for Graphics Set Top of Form Set Top of Form and Page LengthSet Page Length in Inches Set Page Length in Lines Set Skip Perforation Cancel Skip PerforationThis command cancels Set Skip Perforation ESC N This command sets the barcode parameters to the printer Setup Barcode ParameterPrinter Control Deselect Printer Barcode Type Unit Module Width Dots Dec Hex Wire Setup Barcode Data Dec Name Dec Hex Description Font Selection Character Set Select an International Quality Font 248x Select Near-Letter249x Select Letter-Quality Font Select Character Style Parameter range Assign Character TablesFunction Table/Code Text Print Mode Begin or End Double-high Printing Select JustificationDelete Text Off Dec Hex Print Style Change Graphics Mode Command Pin Graphics Mode 248x onlyNormal Density Bit Image Graphics Dual Density Bit Image Graphics Dots per Inch Density Dpi Equivalent Command Set Graphics Mode Horizontal Tab BackspaceSet Horizontal Tab Stops Set Absolute Print Position Vertical Movement Format Other Commands Setup Barcode Data Setup Barcode ParameterSelect Condensed Mode Define Download Characers Epson Emulation Mode Printer Commands Select Standard Character Set Character SetSelect Block Graphics Character Set Code Page Set Print from CodeDecimal Hexadecimal Character Size and Spacing Factor 112 Value Variable/FeatureCharacter Style Custom Characters Speed/Word Size Stored graphics data in one dot column bufferDots per inch/Density Execute Horizontal Tab Backspace Carriage ReturnSet Horizontal Tabs by Characters Pitch 2480 2481 Indent from Left Margin Set Horizontal Tabs by Dot ColumnsPitch Shift Increment Move to the Left Set Multiple Print PositionsMove to the Right Begin Uni-directional Printing Set Page Length in Inches Cancel Skip Over PerforationSet Page Length in Lines Select Skip Over Perforation Cancel Paper-out Sensor Cancels Half-speed PrintingSelect Print Suppress Mode Cancel Print Suppress Mode Eject Parallel Interface Voltage Levels Parallel Interface Computer to Printer Communication 1329605 10 ft 1427498 20 ft Printer Pin ConnectionsComputer Pin Line Description Parallel Pin Assignments Init Timing Universal Serial Bus Interface How to Connect the RS-232C Serial InterfaceSerial Interface Serial Interface Option Following illustration shows the RS-232C serial cable Pin Signal DescriptionSerial Cable Pin Assignments RS-232C Serial Interface Cable RS-232C Voltage Level Range Using an IBM AT Personal Computer RS-232CSerial Communication Parameters RS-232C Serial Data Frame Considerations RS-232C 100Data Transmission Start and Stop Bits Data Flow Control Errors101 XON/XOFF Protocol Timing 102 103 Serial Computer Configuration Recommendations RS-232COS/2 1.2 OS/2 2.0 104 248x Printers How Dots Are Added in NLQ ModeDesigning Draft and NLQ Characters 105 Vertical Lines 106 Intersections of Vertical and Horizontal Lines 107 Diagonal Intersecting Horizontal Line 108 109 Designing Fast Draft Characters Designing NLQ II CharactersDownloading Characters Initializing the Download Area 110Downloading a Draft/NLQ Character Set Part One Calculating Count 1, Count Bit Bit Values Functions 111Part Two Specifying the Download Data Printable 112 113 Designing and Downloading the Draft/NLQ Copyright Symbol 114 Downloading an NLQ II Character Set 115 116 Printable Data 117Bit Functions 118 119 Designing and Downloading Characters 249x Printers120 Downloading a New Font Design Considerations 121Font Descriptor Byte Download Sequence 122 123 Lookup Table Managing the Download Area124 125 Designing Monospaced Fast Draft Characters MSB LSB 126 Creating the Character Data Use the following command to initialize the download area127 Downloading the Character Data 128Downloading the Font Descriptor Byte For more information about the Font Descriptor Byte, see Creating the Lookup Table Data 129Downloading the Lookup Table Data Send the following lookup table information to the printer Printing the Character Designing Monospaced Draft Characters130 LSB MSB 131 Initializing the Download Data 132 133 134 135 Designing Proportionally Spaced Characters LSB MSB 136 Compressing the Character 137 138 Send the following lookup table example to the printer 139 140 141 Designing Enhanced Letter Quality Characters 142 1FFFF0 143 144 145 146 Barcode Function Barcodes Barcode Setup Command Is a space module Is a bar module 149Barcode Type Value 248x 249x Value 248x space 249x space Module adjustment Is the space width adjustment factor Minimum Minimum v1 Printer Model Value Values 151 Data Transfer Command 153 Barcode Symbologies 12, x0C 13, x0DN2 value Data character set Character Hex 155 Valid EAN-13 command N2 value Invalid EAN-13 command 157 Valid EAN-8 command Barcodes To 255, x01 to xFF 159 X53 161 Valid Code 39 command Lowercase ’a’ is not a valid data character for Code Invalid Code 39 command Interleaved 2of5 163 Valid Interleaved 2of5 command 11, x0B Invalid Interleaved 2of5 command165 Valid UPC-A command 167 Character N1 value b0=1 169 Valid Postnet command ’-’ dash is an invalid character for Postnet Postnet To 255, x02 to xFF 171 Function Hex Data character sets Hex Character Code 173Data character set a Data character set B Data character set C 175 Valid Code 128 command 177 Invalid Code 128 command Valid Code 128 command using multiple character sets 179 X0005 181 Example 183 Space width adjustment = default 185 Barcodes Code Pages Code 189 Code Page 437G Code 191 Code 193 Code Page 853T Code 195 Code 197 Code 199 Code 201 Code 203 Printing a Code Code Command Output from the previous example is shown below 205 Set Font Global, ESC 248x Font Global IDs FGIDs Decimal, Hex and Byte Decimal 207 Gothic 249x Font Global IDs FGIDs Decimal, Hex and Byte Decimal 209 Pitch 211 Decimal Hex Code Print Quality Decimal Hex 213 Select Fast Draft Interaction of Set Font Global and Set Print Quality 215 Character Sets 1 Character Set 217 Code Pages Glossary Glossary Data flow control RS-232C Data frames serial Data packets Numerics See serial adapter Index Index Reader’s Comment Form Business Reply Mail