Sometimes I feel like I've headed off a cliff wondering why I'm where I am halfway down to the water.
The dual boot exercise was to start with MACH3 and eventually migrate to LinuxCNC. The PMDX-126 with dual parallel port inputs and a number of other nice features works well with MACH3 and would also work with the USB Ethernet SmoothStepper. Unfortunately the SS is not supported under LinuxCNC. I have a PMDC-125 with USB Smooth Stepper running my JGRO CNC Router. So I bought a second parallel port card (low profile) which is more than enough I/O for what I need. That all works just fine with LinuxCNC and the PMDX-126. But it's turning out that the PCs I have show a latency of 25uS with on board video and go up to almost 100uS with 3 different low profile video boards. The stock motherboard video with WIN-XP can do 75Khz under MACH3. The Smooth Stepper can also do way more. I need at least 55kHz to get full speed from my DC Servos. Looks like 20 kHz step rate is the max with the existing hardware under LinuxCNC. Therefore under LinuxCNC I need something with say an Ethernet interface that has two ribbon cables compatible with PC Parallel port pinout so the latency isn't an issue? Anything out there or am I stuck with WIN-XP and MACH3? Changing out the PMDX-126 is not an option. Thanks John _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
