On Sat, 2011-07-30 at 16:34 +0430, Farzin Kamangar wrote: > Hello EMC users, > I have difficulty when adding additional parallel ports (other than the > parallel port on mother board) and configuring them as input. When I monitor > the pins 2 to 9 they are > always off, but the pins 10 or 11 are on.
If the parallel port in question indicates that ECP, EPP or Bi-directional is supported, then my guess is that input on pins 2-9 should work. One problem might be that for input, you may need a pull up resistor on each input pin to pull the pin up to 3 or 5 volts. Then have your input device sink the pin to ground for the active state. Most PCI cards I have seen are 5 volt compatible. Size the resistors to be greater than the sinking current limit of the input device, so the device will not try to sink more current than it can handle (V=IxR, ie 5=.003xR or 5/.003 = 1.6kOhms). The parallel port input pin should not sink or source much current, but you may need to use diodes to protect against reverse voltage (series blocking) and/or over voltages or spikes (Zener shunt). I am not an expert on this so the above should just give you a start on do your own research. These links might be handy: http://www.beyondlogic.org/spp/parallel.htm http://wiki.linuxcnc.org/cgi-bin/emcinfo.pl?EMC2_Supported_Hardware (See section "PCI and PCIe Parallel Port Cards") Posting more details of your parallel port card and what it is connected too, might help us to give better advise too. -- Kirk Wallace http://www.wallacecompany.com/machine_shop/ http://www.wallacecompany.com/E45/index.html California, USA ------------------------------------------------------------------------------ Got Input? Slashdot Needs You. Take our quick survey online. Come on, we don't ask for help often. Plus, you'll get a chance to win $100 to spend on ThinkGeek. http://p.sf.net/sfu/slashdot-survey _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
