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Field Description
Flow control Set your Terminal Server port flow control to Hardware. Then set your printer to use ‘DTR Pacing’ or ‘Hardware’ or ‘Ready/ Busy’ flow control. Use the RS-232 printer cable pinout shown in the Cabling Guide (Appendix C), as this will save a print job if the printer is turned off or the cable becomes detached.
Name The LPD client, as a reference to the printer, will use what you assign here. This is the printer queue name on the Terminal Server.
Access Set this field to Remote. This sets the port of the terminal server to listen for connections coming from the network. There will be an INETD process running on the terminal server that does the listening.
You can check on the status of this process by looking at the NETSTAT screen of the terminal server’s STATS menu (or show net).
Mode The port of the terminal server will operate in a raw TCP/IP mode.
Local port The INETD process running on the terminal server for this port is listening for TCP/IP connections on TCP port 515 (this is the LPD service number).
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Accessing the Printer
The client is the machine that contains the file to be printed and may be running one of a range of operating systems and applications. The client must support LPD, Unix systems normally include a version of LPD and there are a number of TCP/IP applications for DOS/ Windows ® that also support LPD.
When printing via LPD the client refers to the printer by IP address (or the name associated with this address from the host table) and printer name or queue name. This may take one of the following forms:
• The name of the terminal server and no queue name or port number. This will cause the print job to be printed on the first available LPD port on the terminal server of this name. The Name field in the Port Setup Menu does not need to be set.
• The name of the terminal server followed by a port number. For example if the queue name is server_name9 (or server_name09) then serial port 9 will receive the print job. Please note that in this example, the Name field in the Port Setup Menu need not be set. • The printer name as set in the Name field of the Port Setup Menu. More than one serial port may have the same name allowing the server to create a hunt group of printers. The first available port to match that queue name will receive the print job.
A special feature of LPD with terminal servers is the ability to do carriage-return and line feed mapping at the server. This is accomplished by having a + appended to the client queue name and is valid for all of the above methods of access. Alternatively, you may enable the CR to CR LF mappingoption for the port.
Note
There is a maximum limit of 30 LPD connections per server, which may be distributed to all of the available LPD ports as required. If the maximum is exceeded then the request is rejected and the connection is closed.
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LPD printing from DOS/Windows ®
At present it is possible to print from Windows ® or DOS although this will normally be accomplished via a separate application program like PC/TCP or Netmanage Chameleon. The new versions of Windows ® type operating systems either have or intended to have TCP/IP built into the operating system. Windows NT ® has a built-in LPD utility, and there are shareware packages on the Internet for Windows ® 95/98 (check our website).
The documentation for each application or operating system should allow users to configure and use it with the Terminal Server. The obvious advantage of using LPD to print is that the server can be used to connect a printer that will be shared between both DOS/Windows ® and Unix machines.
Under Windows ® the printer will be available from within other applications via the File option of the Windows ® menu bar.
The actual printer will be referenced by the Name of the terminal server serial port or, by the terminal server and port number in the same way that Unix uses the Name.
The server IP address should be included in the Host table before trying to setup the actual printer port.
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LPD Printing from BSD Unix and Linux
This section should give you some idea of how to set-up printing via LPD on a Unix host. However, this will not be universally true as different versions of Unix have different configuration requirements. You may also wish to consult your Operating System documentation before attempting to add LPD.
The Unix host should have a printer database, for BSD and Linux type systems this will be the file /etc/printcap and there should be an entry within this file for the server’s LPD port that looks something like the following:
#term_serv LPD Printer on serial port 16
Laser1|IOLAN LPD printer 16:\
:rp=LPD_printer:rm=term_serv:lp=:sf:\
:sd=/usr/spool/LPD/LPD_printer:\
:lf=/usr/spool/LPD/term_serv16/log:
Printing could then be accomplished using the following command: