Siemens SINUMERIK 840D sl Function Manual

Also see for SINUMERIK 828D Turning: Diagnostic manual Function manual Equipment manual Programming manual Operating manual

Two rotary axesTwo general solutions exist for two rotary axes. The control itself chooses these two solutionpairs such that the orientation angles resulting from the frame are as close as possible to thespecified angles.The two following options are available for specifying the angles:1. If $TC_CARR21 or $TC_CARR22 contains a reference to a rotary axis, the position of thisaxis at the start of the block in which the toolholder is activated is used to specify the angle.2. If $TC_CARR21 or $TC_CARR22 does not contain a reference to a rotary axis, the valuescontained in $TC_CARR13 or $TC_CARR14 are used.ExampleThe control first calculates an angle of 10 degrees for one axis. The specified angle is 750degrees. 720 degrees (= 2 * 360 degrees) are then added to the initial angle, resulting in afinal angle of 730 degrees.Rotary axis offsetRotary axis offsets can be specified with system variables $TC_CARR24 and $TC_CARR25.A value not equal to zero in one of these parameters means that the initial state of theassociated rotary axis is the position specified by the parameter (and not position zero). Allangle specifications then refer to the coordinate system displaced by this value.When the machining plane is changed (G17 - G19), only the tool length components of theactive tool are interchanged. The components of the toolholder are not interchanged. Theresulting tool length vector is then rotated in accordance with the current toolholder and, ifnecessary, modified by the offsets belonging to the toolholder.The two toolholder angles α1 and α2 are determined using a frame, independent of the activeplane currently selected (G17 - G19).Limit valuesLimit angles (software limits) can be specified for each rotary axis in the system variable set($TC_CARR30 to $TC_CARR33) used to describe the toolholder with orientation capability.These limits are not evaluated if both the minimum and maximum value is zero.If at least one of the two limits is not equal to zero, the system checks whether the previouslycalculated solution is within the permissible limits. If this is not the case, an initial attempt ismade to reach a valid setting by adding or subtracting multiples of 360 degrees to or from theinvalid axis position. If this is impossible and two different solutions exist, the first solution isdiscarded and the second solution is used. The second solution is treated the same as thefirst with reference to the axis limits.If the first solution is discarded and the second used instead, the contents of $P_TCANG[1/2]and $P_TCANG[3/4] are swapped, hence the solution actually used is also stored in$P_TCANG[1/2] in this case.The axis limits are monitored even if the axis angle is specified instead of being calculated.This is the case if TCOABS is active when a toolholder with orientation capability is activated.W1: Tool offset18.6 Toolholder with orientation capabilityBasic Functions1464 Function Manual, 01/2015, 6FC5397-0BP40-5BA2