User`s manual

CBM-292/293 User’s Manual
35 CITIZEN
8.2 Input and Output Signals
(1) TXD
If the input buffer on the printer side has 128 or less remaining bytes while receiving the data, the
DC3(13h) data reception disabled signal will be output. If the input buffer has 256 or more remaining
bytes, the DC1(11H) data reception enabled signal will be output to the host side. At the time of
sending the status information, if DTR/DSR control is selected, the data will be sent after confirming that
DSR is Space. If DTR/DSR is not selected, the data will be sent, ignoring DSR.
(2) RXD
A serial received data signal. If there is a framing error, overrun error, or parity error, that data will be
printed as "?".
(3) DTR
When this signal is Space, write a data or command. If written at Mark time(BUSY), an overrun error
will result, ignoring the data. The data can be written in the input buffer even during printing.
Mark(BUSY) will be generated at power-on, during test printing, at on-line mode, or at reset time as
well.
(4) DSR
Set to Space when sending the data from the printer to the host in printer status transmission. When set
to Mark, the printer will wait to transmit until the Space status takes effect, without transmitting the data.
Ignored in case of X-ON/X-OFF control.
(5) GND
A signal line at the same level as the GND for the circuit driving power.