First Alert ACTION T-1000 - Manual (Page 68)

Technical Specifications
Printing enabled/disabled signals and control conditions
The table below shows the relationship between printing being enabled
or disabled, and the on line/off line condition, the printer select signal
(SLCT IN), and the receipt of data on/off control character, DC1/DC3.
ON LINE SLCT IN DC1/DC3 ERROR BUSY ACKNLG Printing
(Indicator) (Data (Disabled/
o n ) on/off enabled)
control)
on line
Low (Sw. DC1/DC3 High High/Low Pulsed ea. Enabled
2-1/ (no effect) char. (normal
i n t e r f a c e ) cond.)
o n l i n e High DC1 High High/Low Pulsed ea. Enabled
Recv’d char
on line H i g h DC3 High High/Low Pulsed ea. Disabled*
Recv’d char.
off line High/Low DC1/DC3 Low High Not Disabled
(no effect) (no effect) generated
*Even though printing is disabled, data characters are received and acknowledged,
since the printer
IS
looking for another DC1 character, which would allow it to resume
printing.
6-8 Technical Specifications