Section 6. Interface Specifications
RS232C Interface Signals
PIN DIRECTION SIGNAL DEFINITION
1 Reference FG (Frame Ground)
2 To Host TD (Transmit Data) - Data from the printer to the host computer.
Sends X-On/X-Off characters or status data (Bi-Directional
protocols).
3 To Printer RD (Receive Data) - Data to the printer from the host computer.
4 To Host RTS (Request to Send) - Used with Ready/Busy flow control to
indicate an error condition. RTS is high and remains high unless
the print head is open (in this case, RTS would return
to the high
state after the print head is closed and the printer is placed back
on-line) or an error condition occurs during printing (e.g., ribbon
out, label out).
5 To Printer CTS (Clear to Send) - When this line is high, the printer assumes
that data is ready to be
transmitted. The printer will not receive data
when this line is low. If this line is not being used, it should be tied
high (to pin 4).
6 To Printer DSR (Data Set Ready) - When this line is high, the printer will be
ready to receive data. This line must
be high before data is
transmitted. If this line is not being used, it should be tied high (to
pin 20).
7 Reference SG (Signal Ground)
20 To Host DTR (Data Terminal Ready) - This signal applies to Ready/Busy
flow control. The printer is ready to receive data when this pin is
high. It goes low when the printer is off-line, either manually or due
to an error condition, and while printing
in the Single Job Buffer
mode. It will also go low when the data in the buffer reaches the
Buffer Near Full level.
Cable Re
uirements
DB9 DB25 HOST INTERCONNECTION PRINTER
1 1 FG
←⎯⎯⎯⎯→
1 FG (Frame Ground)
2 3 RD
←⎯⎯⎯⎯⎯
2. TD (Transmit Data)
3 2 TD
⎯⎯⎯⎯⎯→
3 RD (Receive Data)
8 5 CTS
←⎯⎯⎯⎯⎯
4 RTS (Request to Send)
7 4 RTS
⎯⎯⎯⎯⎯→
5 CTS (Clear to Send)
4 20 DTR
⎯⎯⎯⎯⎯→
6 DSR (Data Set Ready)
6 6 DSR*
←⎯⎯⎯⎯⎯
20 DTR (Data Terminal Ready)
5 7 SG
←⎯⎯⎯⎯→
7 SG (Signal Ground)
*This connection at the host side of the interface would depend upon the pin that is being used as the Ready/Busy signal by the
driving software.Typically,on a PC, it would be either CTS(pin5) or DSR(pin6) on a DB-25 connector.
READY/BUSY FLOW CONTROL
Ready/Busy
is
the hardware
flow
control
method
for
the
serial
interface
on
the
Se
printers.
By
raising/lowering
the
voltage
level
on
Pin
20
of
the
RS232C
port,
the
rinte
notifies
the
host
when
it
is
read
to
receive
data.
Pin
4
RTS
and
in
20
Pa
e 6-6 SATO
“Se”
Print En
ines
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