The PLOTOPT command lets you access the drawing plot-out related options via a GUI dialogue window operation. Some of these options are controlled by specific system variables.

PLOTOPT will pop up the dialogue window as shown below:
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The following describes these screen items in details.

Plotter Output Options

There are a few options in this group.

End point swapping optimization

If this option is enabled, TwinCAD will check for every output vector for nearest end point swapping optimization. That is, if a plotting vector should be output to move the pen from A to B, while the position B is nearer to the current pen position, it will be output to move the pen from B to A. This optimization will reduce the total length of pen movement and thus will reduce the total time spent in pen movement.

However, if the output device is not a real pen plotter, this optimization will not bring you any real benefit. You may like to turn it off for faster output processing. Likewise, if your application requires the output pen stroking sequence to follow a predefined way, you will have to turn this option off.

Solid filled with unidirectional lines

If this option is enabled, and an area must be filled with scan lines for the solid color, then TwinCAD will fill it with unidirectional scan lines, instead of swinging the scan lines bi-directionally to save the pen-up and pen-down operation. This option is suitable for non-pen plotter output.

Chord Segmentation Control

If the plotter does not support circular arc plotting command (as indicated by the loaded PDF file), TwinCAD will replace these circular arcs with successive chord lines. You may control the fineness of this circular arc segmentation by specifying

  • Max. Angle     The maximum chord angle allowed.
  • Length     The maximum length of the chord.

Transmission Control

TwinCAD conducts the parallel/serial port communication via Windows API calls, which manipulate a queue buffer for the data transmission. If you are using the serial communication port for the plotting device, you may specify the size of this transmission queue. The maximum size of this queue is 65535 bytes. The internal default is 8192 bytes.

Whenever a plotting command code is generated and is to send through the communication port, it will be stored first into the transmission queue for Windows to transmit it through the line transparently. After all codes are generated to the transmission buffer, TwinCAD will be free from waiting and be able to continue its CAD service, while Windows does the transmission in the background. So, the larger the buffer, the sooner TwinCAD will end the plotting processing.

However, if you are going to plot several drawings in a batch processing manner via the use of a TCL application program or pre-written command script, or there are chances that other Windows applications may also use the same communication port for the same purpose, you should make a check on the option: "Wait for queue empty", such that TwinCAD will continue locking the communication port for transmission until the transmission queue is empty. This will prevent the corruption of the transmission queue after TwinCAD has logged off the channel.

PRPLOT Command Procedure

You may issue PRPLOT command to print out the current drawing to the printer. However, there are two different operating procedures:

  • DOS version compatible     If you are familiar with the TwinCAD's DOS version, or you have a TCL application that relies on the compatibility with the DOS version, you may choose to process the PRPLOT command in the DOS version compatible way (which pop-ups a dialog window first).
  • Standard procedure     The standard PRPLOT command procedure will let you setup the drawing frame on the paper first, where you may enter options to configure the printer, paper size and other things. It is more compliant with the Windows convention in printing documents.

If the PRPLOT command procedure is not driven by a command script, TwinCAD will call Windows Common Dialog to access the printer, where you may have the last chance to change settings or cancel the printing. You may skip this dialog by making a check on the option: "Suppress Print Dialog".

Other Buttons

After completing your option setup, you have to press the [OK] button to confirm the change and terminate PLOTOPT. Or, you may press the [Cancel] to quit PLOTOPT operation. You may also press <ESC> key or the right mouse button to quit the operation.

Special Notes:

The PLOTOPT command is an external command provided by the TCL program file "PLOTOPT.TCL" or "PLOTOPT.TCA". Either file must be present in the COMMANDS sub-directory where the TwinCAD resides. If you can not issue PLOTOPT command, you may solve the problem by copying the "PLOTOPT.TCL" or "PLOTOPT.TCA" to the COMMANDS sub-directory.

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