Datamax-O'Neil S-Class User Guide - Manual (Page 17)

S-Class 9
3.1.1 Automatic Parser Mode Detection
From the factory, the printer will automatically interpret the data
received from the host to set the Parser Mode.
 Note: When set to ‘Auto,’ the printer assumes its parser mode according to
the first character received. If the first character is a < (ASCII control
character 3C, as transmitted by most ticketing software packages),
the printer will assume the desired DTPL parser mode. However, in
certain cases (for example, if a font download is executed following
power-up), a received character may cause an unexpected parser
mode which can falsely appear to be a communications problem.
If you want to force the parser mode, see Section 4.3.
More information on identifying the parser mode setting is available in
Section 5, under ‘no communications / not printing via software.’ If
you have any questions or are unable to establish communications,
contact Datamax-O’Neil Technical Support for help.