Star Micronics SCP700 Series Programmer's Manual page 19

17
Error Condition
Upon detecting an error, the printer immediately sets DTR to "MARK" and
goes off-line. If the printer recovers from the error, DTR is set to "SPACE" and
the printer goes back on-line.
When paper is out
RXD
OFF LINE ON LINE
DTR
Printing
Recovery
Error
Printer error
Power ON