Epson DFX-5000 User Manual page 204

Printing enabled/disabled signals and control conditions
The table below shows the relationship between printing being
enabled or disabled, the on line/off line status, and the receipt of
the data control characters, DC1 or DC3.
*While printing is disabled, character data is being received and
acknowledged so that the printer can look for another DC1
character, which would allow it to resume printing.
Technical Specifications
B-10