Epson LQ 1050 - B/W Dot-matrix Printer Technical Manual page 25

Table 1-18 shows the printer select/deselect (DC l/DC3) control, including relations among ON-LINE,
ON-LINE SW
OFF-LINE HIGH/LOW
ON-LINE HIGH
L O W
NOTES: 1. In the Table 1-18, it is assumed that no ERROR status exists other than that attributable
to OFF-LINE mode.
2. Once the printer is deselected by the DC3 code, the printer will not revert the selected state
unless the DC 1 code is input again. (In the deselected state, the printer ignores input data
until the DC 1 code is received.)
3. The DC 1 and DC3 codes are enabled only when the SLCT-IN signal (Input Connector No.36
for the parallel interface unit) is HIGH and printer power is initialized.
4. If the SLCT-IN signal is LOW when the printer is initialized, DC l/DC3 printer select/deselect
control is invalidated, and these control codes are ignored.
5. If the SLCT-IN signal is HIGH and is not set to LOW by jumper 6 when printer initialized,
the printer starts from the selected (DC 1 ) state.
Table 1-18. Printer Select/Deselect Control
ERROR
DC l/DC3 LOW
DC 1 HIGH
HIGH
DC 1 HIGH
DC3 HIGH
1-16
ACKNLG
BUSY
No pulse
HIGH
Pulse output
after entry
(During data
entry)
Pulse output
after entry
(During data
entry)
LOW/HIGH Pulse output
(During data after entry
entry)
Pulse output
LOW/HIGH
(During data after entry
entry)
DATA ENTRY
Disable
Enable (Nor-
Enable
(Waits DC1.
See Note 2)
Enable (Nor-