Dirk, The parallel port is not practical, at least for the lasers I am using as the minimum PWM frequency supported is 5Khz. The Synrad lasers accept a PWM reference signal in the range of 5-25Khz. It is internally clocked at 5Khz as far as adjusting laser power, so there is no performance difference resulting from increasing the frequency of the PWM.
With the Hostmot2 drivers this is very easy to generate because it includes a pin for setting the frequency of the PWM and is independent of the period of the servo or base threads. With the 7i43 board, which connects via the parallel port, I have been able to get the servo thread to run as fast as about 350 micro seconds, although I typically set it to 400. The 5i20, with the PCI interface, can easily run faster than 200 microseconds (assuming the processor is up to it), which is the maximum rate at which the laser power can be changed. Regards, Eric Interesting, I need a PWM signal to drive the laser. I haven't really thought about it yet. But I was thinking about using an arduino for it. Although this might be problem because of RT issues over the serial port. Have you tried using a parallel port? Or did you start with a Mesa board directly? ------------------------------------------------------------------------------ Stay on top of everything new and different, both inside and around Java (TM) technology - register by April 22, and save $200 on the JavaOne (SM) conference, June 2-5, 2009, San Francisco. 300 plus technical and hands-on sessions. Register today. Use priority code J9JMT32. http://p.sf.net/sfu/p _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
