https://forge.codesys.com/forge/talk/Motion/thread/c4b019c165/2020-02-27T18:33:28.417000ZRecent posts to BUG2: CoDeSys Axis-modulo tracking error2020-02-27T18:33:28.417000Z2020-02-27T18:33:28.417000ZAnonymoushttps://forge.codesys.com/u/*anonymous/https://forge.codesys.comae3914a757d5cbe3ae18e37f987b8e8a41ca9d19

<div class="markdown_content"><p><em>Originally created by:</em> Nicolai_Hanssing</p> <p>3S Software has acknowledged, reproduced and solved the bug described above. The residual issue is solved by Hilmar Panzer in SM_DriveBasic.lib ver. 1.9.4.1 wich has yet to be released.</p> <p>To make sure your not affected by the bug, just confirm that your modulo-value in drive increments are a whole noumber. This can be read out from the AXIS_REF.iRestNumerator == 0.</p> <p>Regards</p> <p>Nicolai Hanssing, M.Sc.</p> <p>Delta Elektronik A/S</p> <p>Denmark<span>[/b]</span></p></div>

2020-02-27T18:33:25.273000Z2020-02-27T18:33:25.273000ZAnonymoushttps://forge.codesys.com/u/*anonymous/https://forge.codesys.com560f145e336f14ce76a3d3322cffc6d0b3654746

<div class="markdown_content"><p><em>Originally created by:</em> Nicolai_Hanssing</p> <p>Setting up an axis with positionmodulo, where the physical resolution pr turn is not a integer in drive-increments causes the position to drift when multiple turns are performed on the axis.</p> <p>Motor: 4096 inc/rev</p> <p>Gearing 640:28</p> <p>TechUnits: 360 dgr modulo =&gt;</p> <p>.iRatioTechUnitsNum = 63</p> <p>.dwRatioTechUnitsDEnom = 16384</p> <p>.fPositionPeriod = 360</p> <p>.dwOneTurn = 93623 (Wich is not precise)</p> <p>.iRestNumerator = -9</p> <p>It is clear that after 63 full turns you will have a integer-no of incrments:</p> <p>No increments = 360<em>63 / (63/16384) = 360</em>16384 = 5898240</p> <p>And the AXIS_REF.iTurn also reaches this number (63) before roll-over, but the </p> <p>position in AXIS_REF.fActPosition still does not track correctly.</p> <p>Axis started in:</p> <p>.dwActPosition = 0 inc</p> <p>.fActPosition = 0 dgr</p> <p>After running for some time:</p> <p>.dwActPosition = 834859476 (Raw 32bit position from drive)</p> <p>.fActPosition = 89.151 dgr (Not correct - I think)</p> <p>If I perform modulo calculations on that I get: 94.049 dgr as ActPos as correct</p> <p>position.</p> <p>But if I calculate by using .dwOneTurn I get: 89.15dgr as ActPos!</p> <p>Clearly CoDeSys is not tracking the modulo residuals correctly .....</p> <p>When the roll-over occurs the variable .iPosOffSetForResiduals get updated every modulo turn, the resudual value shifts by dwOneTurn. </p> <p>But when .iTurn rolls over .iPosOffSetForResiduals does not get corrected by</p> <p>'iRestNumerator' as it should since:</p> <p>iRatioTechUnitsNum * dwOneTurn = 5898249 = fPositionPeriod*dwRatioTechUnitsDEnom - iRestNumerator</p> <p>Am I completely of the bat here?</p> <p>Or is this a bug in CoDeSys Softmotion?</p> <p>Nicolai</p></div>