bstobie Posted June 12, 2013 Share Posted June 12, 2013 Hi folks, I want to create a 1D compensation table that has a source motor with a bipolar range. Page 186 of the Turbo PMAC User Manual says - "If the motor has a travel range to the negative side of zero, and compensation is desired here, these entries should be made as if they were past the positive end of the motor range. For instance, if the motor travel were +/- 50,000 counts and a table entry was to be made every 500 counts (so 200 entries total), the table would be set up with a DEFINE COMP 200,100000 command. The first 100 entries would cover the 500 to +50,000 count range, and the last 100 entries would cover the -50,000 to 0 count range. (Usually the table is referenced so there is a zero correction at the source motor zero position, so the last entry in the table should be 0.) Essentially, the -50,000 to 0 range would be mapped into the +50,000 to +100,000 range." So if I had (say) a span of -100 to +100 = 200, and 10 table entries, I would use the command (source = #1, target = #2) DEFINE COMP 10, #1, #2, 200 1 Correction at 20 cts 2 Correction at 40 cts 3 Correction at 60 cts 4 Correction at 80 cts 5 Correction at 100 cts 6 Correction at -100 cts 7 Correction at -75 cts? 8 Correction at -50 cts? 9 Correction at -25 cts? 10 Correction at 0 cts? This seems to comply with the above description, but the +ve half of the table has entries 20 counts apart, and the -ve half of the table has entries 25 counts apart? Link to comment Share on other sites More sharing options...
steve.milici Posted June 12, 2013 Share Posted June 12, 2013 A 10 entry table over 200 cts will be the following: DEFINE COMP 10, #1, #2, 200 1 Correction at 20 cts 2 Correction at 40 cts 3 Correction at 60 cts 4 Correction at 80 cts 5 Correction at 100 cts 6 Correction at -80 cts 7 Correction at -60 cts 8 Correction at -40 cts 9 Correction at -20 cts 10 Correction at 0 cts For the full range you want to use: DEFINE COMP 11, #1, #2, 220 1 Correction at 20 cts 2 Correction at 40 cts 3 Correction at 60 cts 4 Correction at 80 cts 5 Correction at 100 cts 6 Correction at -100 cts 7 Correction at -80 cts 8 Correction at -60 cts 9 Correction at -40 cts 10 Correction at -20 cts 11 Correction at 0 cts You may even want to make it somewhat bigger than your actual range and pad the center of the table with dummy entries in case of overtravel: DEFINE COMP 12, #1, #2, 240 1 Correction at 20 cts 2 Correction at 40 cts 3 Correction at 60 cts 4 Correction at 80 cts 5 Correction at 100 cts 6 Dummy correction after +/-100 cts 7 Correction at -100 cts 8 Correction at -80 cts 9 Correction at -60 cts 10 Correction at -40 cts 11 Correction at -20 cts 12 Correction at 0 cts Link to comment Share on other sites More sharing options...
bstobie Posted June 13, 2013 Author Share Posted June 13, 2013 Thanks - much clearer for me now. Link to comment Share on other sites More sharing options...
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