AutoCAD LT supports Hewlett-Packard HP-GL plotters through an RS-232C serial I/O port. Set the Hewlett-Packard plotters at 9600 baud, with 7 data bits, 1 stop bit, and even parity.
On the 7550 and DraftMaster plotters, follow the Hewlett-Packard instructions to set monitor mode off, remote mode, stand-alone mode, XON/XOFF handshake, direct mode, full duplex, 7-bit data, parity 0 (zero), and 9600 baud. Automatic sheet feed is enabled on the 7550 when an asterisk (*) appears below the Sheet Feed key.
On the 7580, 7585, 7586, and DraftPro DXL/EXL models, set the RS-232C speed selector to 9600 and set parity to on and to even parity, and set eavesdrop to off. Set the Emulate and Expand switches to normal. If roll media is loaded in the 7586, AutoCAD LT advances the paper and draws a cutting line between plots.
Connect the plotter and computer as shown in the following diagram:
If the plotter starts a plot correctly but drops data, draws random vectors, and turns on the error light, there is probably an error in wiring pin 2, 5, or 6 at the plotter end of the cable.
On the 7475 plotter, the effective plotting area is 10.15 by 7.80 inches for A-size paper. Establish the communication modes by setting the switches as indicated in the following table.
| Switch | 1 | 0 |
| B1 | 0 | |
| B2 | 1 | |
| B3 | 0 | |
| B4 | 1 | |
| S1 | 1 | |
| S2 | 0 | |
| D-Y | D (7470/7475 only) |
The 7580, 7585, 7586, DraftPro DXL/EXL, DraftMaster I, 7586B, and 7596A plotters return hard clip limits to AutoCAD LT. This requires two-way communication between AutoCAD LT and the plotter. The plotter sends AutoCAD LT the installed paper's exact plot area, allowing AutoCAD LT to position the plot on the paper based on the actual sheet size. If you turn off the AutoCAD LT request for hard clip limits, AutoCAD LT positions the plot based on the configured paper size. In most cases, if you turn off hard clip limits, you must adjust the configured paper size to reflect the actual printable area of the device. Otherwise, your plot might be clipped. You can adjust the location of the plot on the paper by changing the plot origin.
If your plot is sent through the Windows spooler, AutoCAD LT's request for hard clip limits is turned off because of a conflict with a Windows system printer or because you are plotting to a network port. If you see a warning message, you might have to adjust your configured paper size and plot origin.
AutoCAD LT sends the plot to the currently configured port in the same manner that it sends the plot to a file, and then you can plot directly to plotter buffers or over networks.
In general, a plot is considered a long-axis plot if it requires more than 65,000 plotter steps in the long direction - typically any plot more than 65 inches long, depending on the plotter's resolution. To plot on long paper, AutoCAD LT reduces the resolution to increase the plot size by rescaling the plot data (retaining the number of pixels, but decreasing the pixels per inch) to keep it within AutoCAD LT's 65,000-step limit.
The ADI plotter driver creates long plots by rescaling the plot data sent to the driver, magnifying the data sent to the plotter at a proportional decrease in plot resolution.
The driver sends all vectors to the plotter buffer or hard disk. The pen plotters automatically advance the page to plot each frame.
Follow the instructions in the Hewlett-Packard user's guide. For long-axis, multiframe plotting, you need a black 0.3 mm fiber-tip pen (for plotter paper) or a 0.35 mm drafting pen (for vellum or polyester film) in pen stall 8. Only these pens enable the plotter to detect the registration marks used for frame-to-frame alignment.
Note: When you create a long-axis plot with the 7586B roll-fed plotter, the Out of Limit light comes on occasionally. Generally this is a result of the way AutoCAD LT and the plotter interact when plotting very large drawings.