▌4.3 Exception processing
• Undefined codes
This term refers to the codes ranging from 00H to 1FH in the character code table. If a code in this range that is not defined as a command is input, that code (one byte) is read in and discarded, and subsequent data is processed as normal data.
Example : 30H, 31H, 03H, 32H, 0AH, 33H
If the above data string is input, the printer reads in and discards "03H" as an undefined code.
Note that 0AH is defined as a command (LF). As a result, the data string that is actually processed is: 30H, 31H, 32H, 0AH, 33H
• Undefined commands
If the data following ESC (1BH) or GS (1DH) is not defined as a command, then the two bytes (ESC/GS and the code that follows) are read in and discarded.
Example : 30H, 1BH, 22H, 31H, 32H
If the above data string is input, the printer discards the data 1BH and 22H as undefined commands. As a result, the data string that is actually processed is: 30H, 31H, 32H
• Settings outside the defined range
If a value outside of the defined range is input for a command that takes parameters, that command is ignored and the previous value for that setting remains unchanged. In the case of a command that takes multiple parameters, command processing is halted the moment that a value outside of the defined range is input and subsequent values are processed as normal data.
Example : 1BH, 52H, 15H
If the above data string is input, 1BH and 52H are defined as a command (ESC R), but the parameter 15H is outside of the defined range. As a result, the printer reads in and discards the data string 1BH, 52H, 15H. Accordingly, the previously set international character set is not changed.
