Hi John EMC expects to get four signals, ArcOK, MoveUP or MoveDown and "Height Probe"
Height Probe is used to set the initial pierce height (you don't have any voltage signal at that point) ArcOK is used to make sure that the torch is firing. MoveUP and MoveDown are used to move the torch respectively. You need to take a whole lot of things into consideration when building the circuit, you need to filter interference and if you have High Frequency start you will run into a whole other set of problems. I don't think it would be very productive to go over all the design concepts but if you are serious about building your own system you should probably read through the master5 yahoo group which has some early designs of what became Bob Campbell's (www.campbelldesigns.com) and CandCNC (www.candcnc.com) designs that are commercially available today. If you are just thinking about the cost of buying one of these units ($500-$1000) then that will always be tiny compared to the cost of building/designing your own. Speaking from experience I can say that designing a board which will be able to handle High Frequency is a major operation and that neither of the aforementioned suppliers have boards that can handle HF. In fact as I found out the hard way it was cheaper to buy a new 100A plasma power source and a torch without HF than to get a THC unit which can handle HF. If you do intend to design and build one of these commercially or as a project then stay in touch and hopefully I can provide some info. Regards Jarl On Fri, 2007-10-05 at 06:43 -0500, John Thornton wrote: > Jarl, > > Thanks for the info. Am I correct in assuming that from the hardware > end using your plasma-thc that I only need to supply a raise or lower > to EMC to make it work? > > My current thoughts are to use a voltage divider from the plasma > voltage out pins to reduce the voltage to a 0 to 10vdc range and use > that as an analog input to a plc. Based on the voltage setting in the plc > supply a raise contact or a lower contact. Or continue to pulse up or down > as a hand wheel would till the desired voltage is obtained. If HAL can ignore > this during cornering it should work??? > > Thanks > John > > On 4 Oct 2007 at 7:28, [EMAIL PROTECTED] wrote: > > > To elaborate on what Alex posted: > > > > dallur-thc is an old version of a gantry based plasma config which > > uses classicladder and has basic functionality. > > > > plasma-thc is a newer version which only uses HAL and has things like > > corner height lock, realtime adjustable cutting height and more. > > > > plasma-thc-sim is a simulator config which should enable you to run > > the system without the hardware. > > > > The logic diagram for plasma-thc is maintained in an open office > > diagram which can be found in the plasma-thc config directory. > > http://cvs.linuxcnc.org/cgi-bin/cvsweb.cgi/~checkout~/emc2/configs/pla > > sma-thc/ > > > > > > Regards > > > > Jarl (dallur and rugludallur) > > > > ------------------------------------------------------------------------- > This SF.net email is sponsored by: Splunk Inc. > Still grepping through log files to find problems? Stop. > Now Search log events and configuration files using AJAX and a browser. > Download your FREE copy of Splunk now >> http://get.splunk.com/ > _______________________________________________ > Emc-users mailing list > [email protected] > https://lists.sourceforge.net/lists/listinfo/emc-users ------------------------------------------------------------------------- This SF.net email is sponsored by: Splunk Inc. Still grepping through log files to find problems? Stop. Now Search log events and configuration files using AJAX and a browser. Download your FREE copy of Splunk now >> http://get.splunk.com/ _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
