RE: [CAD_CAM_EDM_DRO] Hp 7475 Plotter Servo's

Hi Vector,

It could very well be a NULL modem cable that's required. I was hoping to
find my manual last night, but failed.

I still have it cabled up to one of my older computers and a serial switch,
so that would be a way to verify what is needed. And the dip switches will
be set up, probably 9600 baud for me.

If the LED is blinking, then it didn't like one of your commands. You might
route the plot commands to a file (still 7475 format), and see what they
look like. First char for initialization is an ESC (which doesn't print
very well in a text file), then two more characters, like I copied in my
email. Then possibly one or two more initialization codes, and then plot
commands.

From DOS, you can "copy" a valid PLT file to the plotter, and that is a
basic test. Baud rate must be set up, of course.

I'd be curious how you made a drag cutter out of a 7475 pen.

Alan KM6VV

> -----Original Message-----
> From: CAD_CAM_EDM_DRO@yahoogroups.com
> [mailto:CAD_CAM_EDM_DRO@yahoogroups.com] On Behalf Of Victor A. Estes
> Sent: Thursday, September 29, 2005 6:20 AM
> To: CAD_CAM_EDM_DRO@yahoogroups.com
> Subject: Re: [CAD_CAM_EDM_DRO] Hp 7475 Plotter Servo's
>
> Alan,
>
> According to everything I have read on the plotter a NULL Modem cable
> is
> required. So I went out and bought a new serial cable with a null modem
> adaptor. Still does not work. This was after I tried making my own cable
> based on the pin outs that I had read would work, no joy. I set the baud
> rate, parity, stop bits, and everything on the dip switches just as I had
> read was the thing to do from several different web sites on turning a
> 7475
> into a vinyl cutter. I'm running windows xp and the driver for it is a
> HPGL/2 driver which I understand will not work. Has to be a straight HPGL
> driver, windows 3.1, 95, and 98 have it. But I thought I would try anyway
> to see if I could get any response fro the plotter. When I failed to get
> it
> to respond out of windows xp I switch to the DOS window and tried to the
> direct commands by activating the COM1 port, still no joy. So I am still
> at
> a loss here. In my original post I did not mention that I made a real
> neat
> drag knife holder for the plotter out of one of the original pins. I want
> to try vinyl cutting with it. If I cannot get that to work then I want to
> take it apart and make the eggbot.
>
> Victor
> ----- Original Message -----
> From: "Alan Marconett" <KM6VV@...>
> To: <CAD_CAM_EDM_DRO@yahoogroups.com>
> Sent: Wednesday, September 28, 2005 6:01 PM
> Subject: RE: [CAD_CAM_EDM_DRO] Hp 7475 Plotter Servo's
>
>
> > Hi Victor,
> >
> > Are you sure a NULL MODEM cable is required? I have a 7475A plotter. I
> > probably haven't plotted with it for 10 years. There is also a switch
> for
> > baud rate, as I recall. Insure that you are talking the proper baud
> rate,
> > parity, stop bits, etc. (which I'm sure you've already checked).
> >
> > I wouldn't mind finding a 7475 plotter that I could experiment with as
> you
> > describe! I even started an EGGBOT project a few years ago.
> >
> > Alan KM6VV
> >