NetWare 4.1/9000 Print Services

B-10
Cabling Printers
Optimal Serial Cabling
It is not necessary for you to use this pin, and using the pin can cause ground
loop problems if the PC and printer are connected to different power sources.
You have a Frame Ground pin only on a 25-pin connector, and it uses Pin 1.
2 TXD (Transmit Data output pin)
The PC sends data (the print job) through this pin which connects to Pin 3 on the
printer. The PC uses Pin 3 on a 9-pin connector and Pin 2 on a 25-pin connector.
This attaches the PC's transmit pin to the printer's receive pin.
3 RXD (Receive Data input pin)
The PC receives XON/XOFF characters through this pin, which connects to Pin
2 on the printer. The PC uses Pin 2 on a 9-pin connector and Pin 3 on a 25-pin
connector. This attaches the printer's transmit pin to the PC's receive pin.
4 RTS (Request To Send output pin)
NetWare print services sets the signal level high for this pin (and the DTR pin)
on the PC and keeps it in that state. The PC uses Pin 7 on a 9-pin connector and
Pin 4 on a 25-pin connector. This signal can be used as a source for a high signal
level to enable certain functions on some printers. If your printer cable connects
this pin to a pin on the printer that requires a high signal level, printing will
function properly. You can achieve the same results by following the steps in
note 12.
NOTE: Early versions of NetWare print services set the signal level high on this pin when
sending data and set the signal level low when not sending data. The timing of the
signal changes caused many problems with printers that require a high signal level
for data input. Beginning with version 1.22R, NetWare Print Services constantly
maintains a high signal level for this pin.
5 CTS (Clear To Send input pin)
NetWare print services uses this pin for its hardware handshaking. The PC uses
Pin 8 on a 9-pin connector and Pin 5 on a 25-pin connector. This pin connects to
the pin on the printer that controls the flow of data. This is generally pin 20 on
the printer, but some printer vendors use other pins (see note 14). If the signal
level is high for this pin, data will be sent to the printer. Data is not sent when the
signal level is low.
NOTE: If this signal level stays low for about 10 seconds while servicing a print job,
NetWare print services reports an “off-line” condition.
6 DSR (Data Set Ready input pin)