Originally Posted by
ChrisVJ
Unfortunately I am not good with electronics. Fix anything physical, yes. Electronics mostly gobbledy goof.
The serial port instructions in the manual are complicated as the gates of hell. Parallel has only one choice to make so I always ran it as parallel. The first problem with parallel was that my new laptops did not appear to recognise the adapter and if they did they still did not offer "Parallel port" as an option so the software could not send a signal to the adapter.
Apparently most of the adapters don't have a time delay so the plotter is overwhelmed by the speed of the download.
I tried the technical dept at Roland but they were vague on old plotters and mostly only could help with music equipment!
My software (Visual Cadd V) seemed to have built in driver originally. Just load it and click "Plot." I am beginning to think that the only way to get this to work is to buy an old desk top with a parallel port and Windows 7, install my drafting program and transfer files on a USB stick! I don't really want to spend that kind of money unless I'm sure it will work!
Visual CADD seems like it was taken over by Corel in 1996 (see
https://techmonitor.ai/technology/co...el_visual_cadd ), bundled with some of their other software, and spun off again. It appears the current owners TriTools are found at
https://visualcadd.net/ and the latest version is 9.0 which is supported by Windows 7 to 11. An upgrade may solve all your problems. The VisualCADD user group can be found at
https://groups.io/g/VisualCADD where you may be able to ask other users about your problems.
You haven't said what model Roland plotter you have, and whether it can be plotted to by other software that is compatible with later versions of Windows. From you description, it may be it isn't supported by later versions of Windows (obsolescence due to drivers not being released for newer versions of Windows by the vendor) rather than it has any hardware faults such as faulty capacitors. There are convoluted solutions for this.
Both parallel and serial ports have always had handshaking (by design) so that you cannot overwhelm your printer with 'fast' data. It spools it out at the fastest rate the printer/plotter/device gulps it in.
You may be able to print to a PDF file with your older version of VisualCADD and then print the PDF file to the plotter using Adobe Acrobat (free) as a workaround. See page 166 in the latest user manual downloadable from the TriTools website at
https://www.visualcadd.net/download/v9_user_guide.pdf.
Buying a separate computer just to run your obsolete version of a CAD program seems like a unwise purchase decision. Alternates are to update your CAD software, think about a virtual machine (using free VM software) that will support your old plotter and device drivers as other far cheaper options.
Advise the model plotter you have, what USB adapter you have tried, and what the last drivers you have been able to find for them both and we can go from there.
Originally Posted by
soarbum
Years ago, software applications could have direct access to the hardware interrupts and could access the pins of the parallel port directly. As time went by, things became more layered and permissions orientated. If your application does not work with the driver for your usb-parallel adapter, it may be impossible to solve without a custom driver. Serial via USB tends to have a lot more support these days as there are still plenty of sensors out there using RS-232. I also think that its less likely that there is any kind of custom signalling going on as compared to direct access to all of the pins of the parallel port. The most common settings for a serial port were 9600Baud, 8 data bits, no parity and 1 stop bit. Your plotter may have small dip switches to set this but if it is fixed, you need to set the laptop settings to whatever the plotter is using.
Most modern issues with USB RS232 serial adaptors are that it only has voltages for 5 volts peak to peak, rather than the standard RS232 12 volts peak to peak found on motherboard ports and separate IO cards. Some of the more pricier ones comply fully with the RS232 standard, most Chinese ones bought online don't. If your plotter needs the full 12 volts swing, both positive and negative, a cheap Chinese USB adapter that only sends out the positive 5 volts part of the pulse will not do the job, often not at all, sometimes intermittently, and sometimes consistently OK.
Parallel ports don't have that issue. They are a bidirectional 5 volt port with handshaking. Drivers are usually universal. I suspect the lack of plotter drivers by the manufacturer for an older model is the only issue here, and there are common software and hardware workarounds for that.