Epson LQ-2550 User Manual - Page 153

Data Dump Mode The printer has a feature to find the cause of communication problems between the printer and application programs. In data dump mode a printout of the codes reaching the printer is produced. 1. To enter the data dump mode, hold down the FORM FEED and LINE FEED buttons at the same time while you turn on the printer. 2. Next, run either an application program or one you have written in any programming language. Your printer prints all the codes sent to the printer in hexadecimal format as shown below: 16 40 1B 52 00 16 74 01 20 20 54 68 69 73 20 6D 70 6C 65 20 6F 66 75 6D 70 20 70 72 69 69 73 20 66 65 61 74 OA 20 20 20 20 20 69 18 6E 50 20 18 65 7708 0610 61 74 61 20 64 74 2E 20 54 68 20 6D 61 68 65 73 5 61 73 79 20 66 6F [email protected]. This is an exa mple of a data d ump printout. Th is feature makes it easy io 3. To turn off the data dump mode, press the ON LINE button to take the printer off line, and then turn off the printer. (The data dump mode can also be cancelled by sending an INIT signal from the computer.) Look at the data dump shown in Step 2. By comparing the characters printed in the right column with the printout of the hexadecimal codes, you can check what codes are being sent to the printer. If characters are printable, they appear as their true ASCII characters. Nonprintable codes, such as control codes, are represented by dots. As an example of how to interpret a data dump printout, look at the first three hex codes on the second line of the printout sample (20 20 54). Each hex 20 represents a space, while hex 54 represents the letter T Check the second line of the right column and you will find the letter T preceded by two spaces. The chart below interprets part of the first line of codes: 1 Hex codes lB40 lB5200 lB7401 1 Command ESC @ ESC RO ESC tl 1 Function Initialize printer Select USA character set Select Epson Extended Graphics 6-6 Troubleshooting