dave wrote: > > How serious is the problem of using the battery, i.e. what is the > expected life of the battery? Is the a real maintenance problem? > Of course, the next question is accessibility to replace the battery and > the cost. > > How do Fanuc people deal with this in the field? > Fanuc recommends replacing the 4 alkaline cells (I'm guessing AA size) every year, while the machine is powered on. What has me worried is the battery only backs up the position count in a memory chip, it doesn't power the encoder. So, if the machine is bumped while control power is off, the alignment would be wrong. I'm not sure, it may correct itself the next time it passes the index position, but there would then be a discontinuity in position at that moment, likely to cause a servo following error.
Also, they have this procedure for indexing the encoder any time the power has been lost (swap motors, replace cables, etc.) You release the brakes (if any) and manually crank the machine to be close to the home position, power the encoder on and then crank it past the home index position. This sets the revolution count to zero over your home position. If I could get this type of encoder to work with the way EMC2 does homing, I'd feel a lot more comfortable with it. A couple months ago I could have gotten a motor with the serial encoder for under $100 on eBay, now it looks like they are all over several hundred $, even the broken ones. Well, I can keep this loaner for a while. Jon ------------------------------------------------------------------------------ Achieve unprecedented app performance and reliability What every C/C++ and Fortran developer should know. Learn how Intel has extended the reach of its next-generation tools to help boost performance applications - inlcuding clusters. http://p.sf.net/sfu/intel-dev2devmay _______________________________________________ Emc-developers mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-developers
