Citizen Systems Citizen CLP 6001 CLP-6001 - Manual (Page 69)

6-10
(2) Ready/Busy system (see the figure)
This is a control system in which the DTR signal is output at Ready
(High)/Busy(Low) level.
Requirements of DTR "High":
•
When the printer is "on line."
•
When the remaining buffer is less than 2K bytes.
However, when the remaining buffer of less than 2K bytes is
detected, the printer keeps a "Low" level until the remaining
buffer is 4K bytes or more.
•
When printer alarms such as the printer switched to "off line"
occur.