User guide

Technical Characteristics
Data Exchange Procedures
The following communications procedures (see Appendix C) are available:
- Free-running with digital Break : XON (DC1)/XOFF (DC3) (default value)
- Free-running with analogical Break.
Free-Running with XON (DC1)/XOFF (DC3) Digital Break
In this procedure, the printer sends two codes to the computer to indicate the
line buffer status. When the line buffer is 500 bytes from capacity, the printer
will send a BREAK signal (interruption of data transmission), using ASCII
code DC3 (XOFF) on TxD (pin 2), to the computer, requesting the
transmission interruption.
If, after DC3 has been sent, the computer continues transmitting, when the line
buffer is 500 characters from capacity, signal DTR (pin 20) will be set OFF
(-V).
When at least 1000 characters have been unloaded (in a print operation), the
printer will send ASCII code DC1 (XON), so that data transmission can
resume (DTR returns to +V).
Free-Running with Analogical Break
In this procedure, the printer sends a Break signal on wire DTR (pin 20) (-V)
when the line buffer is 500 bytes from maximum capacity, requesting the
interruption of data transmission from the computer.
When at least 1000 characters have been unloaded (in a print operation), the
printer inverts the logic level of Break, so that data transmission can resume.
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