Chapter 6. Configuring Printers

This chapter discusses the ways to attach printers to the 7318 and some of the configuration issues. The most fundamental issue is whether the printer will be a serial or a parallel printer. When available, parallel printer interfaces are the easiest to use and offer the best performance. The serial port is more flexible and is more difficult to configure.

Serial Printers

The physical connection issues and transmission issues relating to printers are essentially the same as for terminals.

When using any serial printer, you should use flow control. For an RS-232 interface, use hardware flow control. Since RS-422 does not support hardware flow control, use software flow control (XON/XOFF characters). Printers generally use DTR for hardware flow control, therefore you should use one of the following:

1. Use a cable adapter that routes the DTR signal from the printer to the DCD input signal on the 7318 (like the Terminal adapter, feature code 7904). You should configure the 7318 for DCD hardware flow control (stty cdxon).
2. Use a cable adapter that routes the DTR signal from the printer to the CTS input signal on the 7318. You should configure the 7318 to use CTS output flow control (stty ctsxon).

In the case where the printer supports flow control on some other signal, the cabling should route the signal to either CTS or DCD on the 7318 and the corresponding flow control enabled for the port in the 7318's configuration file.

Parallel Printers

Parallel printers provide better performance than serial printers. However, the parallel interface limits the distance between the 7318 and the printer. To install a parallel printer, you simply plug the printer into one of the two parallel ports on the 7318 and modify the 7318 configuration file with the appropriate reverse telnet parameters. There are no configuration requirements for a printer beyond those associated with using reverse telnet for serial printers. See "Configuring Reverse Telnet Service for Printers" for more information.

Terminal-Attached Printers

Terminal-attached printing requires the following:

1. The terminal serial line attachment to the 7318 must be configured.
2. The auxiliary line between the terminal and the printer must be configured with matching parameters.
3. Flow control between the printer and the terminal must be disabled.

Using the Terminal-Attached Printer Facility saves the use of a port on the 7318 but offers the lowest performance, because the bandwidth is shared with the terminal. The Terminal-Attached Printing mechanism prohibits printing of binary graphics or use of special escape codes for printer setup.