On Oct 28, 2011, at 3:57 AM, Viesturs Lācis wrote: > 2011/10/28 andy pugh <bodge...@gmail.com>: >> On 28 October 2011 01:20, Tom Easterday <tom-...@bgp.nu> wrote: >>> Is there a command or parameter that can be set while EMC/Axis is running >>> that will make it ignore following error (and then after issuing again - >>> pay attention to ferror)? I want to have my servo drive control an axis >>> and I want EMC to ignore it while I do this, then take back over control. >>> But I don't want to have to disable Axis. >> >> You could latch the encoder feedback into a mux2. If you link the >> output to the input then it acts like a sample-hold block (there is a >> sample-hold, but that is s32 not float). If you wire the select pin to >> the homing pin, and the other input to the encoder position, you can >> freeze the feedback. > > It is not clear to me, how exactly the "I want to take control of > particular joint from EMC2 for a while and then give it back to EMC2" > idea is meant to be used and if You want EMC2 to know the actual joint > position even when You are controlling it. > The thing I did for THC purposes - I modified kinematics so that > joints[3] = tran.pos->z + offset and the offset value was set by THC > module. That way Z height was adjusted by THC and EMC2 always knew the > position of joint, displayed it in DRO and also did not allow to > exceed soft limits. > Depending on the way You want to take over control of particular joint > and then then giving it back to EMC2 (does the switch of control > happen in the same joint position, does EMC need to know exact joint > position, when You are controlling it etc), You might do something > similar.
This is for homing my gantry. It has two joints on one axis (the Y axis). I want to have EMC ignore following error, and not control the motors while I send a signal simultaneously to each of the two Granite Devices drive modules which will then home both joints to a hard stop (and come off those hard stops a small amount). The Granites ignore incoming signals while they are doing this so I need EMC to be ok with the fact that it is not commanding the motors and that there is huge following error. Once the Granite is done doing it's homing I want EMC to then search for index on one of the two joints while moving the opposite joint in sync (so the gantry doesn't rack) . By the way, ultimately once we get things working, we will have a THC enabled and I like your idea of the offset. Can you post (or pastebin) your config for how you do the z+offset? Thanks, Tom PS: I found a thread in the mailing list archives talking about options for gantry homing that sounded like there was some work being done in that area. Did anything come of that? Is there anything new on that front in 2.5? ------------------------------------------------------------------------------ The demand for IT networking professionals continues to grow, and the demand for specialized networking skills is growing even more rapidly. Take a complimentary Learning@Cisco Self-Assessment and learn about Cisco certifications, training, and career opportunities. http://p.sf.net/sfu/cisco-dev2dev _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
