Thanks Paul but the driver is not the problem. I've been using the HPGL
Draftsmaster1 driver which works fine with the HI plotter. It's only when I
use a usb to serial adapter instead of a direct serial port that things blow
up. I am wondering if it's something about the the converter which prevents
all plotters from working or perhaps there is some setup that needs to be
changed to make it work.
bigbear
I specifically mentioned "flow control", as it is a configuration
option of a serial port. The same applies to setting the
baud rate, start/stop bits, 8 bit data and so on.
Flow control can be done a couple of ways. There are status signals
on the RS-232 side that are used for flow control at the hardware
level. There is also XON/XOFF method. I would investigate
whether there are any differences between a standard RS-232
interface, and the USB adapter, with regard to settings like that.
Do you have any information on the protocol used by the plotter ?
Have you considered using Hyperterminal, to talk to the plotter
via the USB to serial interface ? If you were debugging a modem
for example, you could send the "AT" command and look for "OK"
to come back, in a terminal session with the device. Perhaps if you
know something of the protocols and supported commands, you can
use that information, and Hyperterminal, to debug the USB
serial port.
Paul
