Printer User Manual

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(14) Input/Output Signals
(15) Connector Pin Assignment and Signal Description
Pin No.
Signal
Name
Function Signal Direction
1 (N.C)
2TDz Line for data which the printer sends to the host
z Logic 1 is a Low level, while logic 0 is a High level.
z It is in the Low (Mark) state when no transmission is in
progress.
Printer →
3RDz Line for data which the printer receives from the host
z Logic 1 is a Low level, while logic 0 is a High level.
z It is in the Low (Mark) state when no transmission is in
progress.
← Host
4 DSR z Input signal from the host
z For the printer to receive data, it must be at “High” level.
← Host
5SGz Ground line for all data and control signals
6 DTR z Output signal to the host
For the READY/BUSY (DTR) protocol or XON/XOFF
(DC1/DC3) protocol + READY/BUSY (DTR) protocol:
z It indicates the ready state for the received data.
z It is at the “Low” level when the receive buffer is near
full, and at the “High” level when near empty.
For the XON/XOFF (DC1/DC3) protocol or RTS protocol:
z After the power is turned on, it is always at “High”.
Printer →
7 CTS z It is an input signal indicating whether or not the data
transmission to the host is possible. However, this printer
does not detect this signal.
← Host
8 RTS z Output signal to the host
For the RTS protocol:
z It indicates the ready state for the received data.
z It is at “Low” when the receive buffer is nearly full, and
at “High” when nearly empty.
For protocol other than the RTS protocol:
z After the power is turned on, it is always at the “High”
level.
Printer →
9 (N.C)
Printer Host
TD
RD
RTS
CTS
DSR
SG
DTR