Motion control C3F_T40254 192-121102 N04 June 2008Change-over (CouplingMode = 2)When using the change-over-function, the curve setpoint value is permanentlydisplayed during coupling, while the current slave position is permanently hidden.Overspeeding and pull-out movement are possible.By specifying the master-related coupling and synchronization position in masterunits, the coupling curve is mapped to a range of any length of the curve. Thismeans that it is no longer fixedly coupled to the curve cycle.Algorithm of the change-over functionThe normalized coupling function begins at the value 0 and end at the value 1 andrises continually in between. It is a 5th order function.The coupling curve does not produce a direct slave setpoint value but produces afactor KE for the weighting of the current curve setpoint value resp. the currentslave position Sa (position at the start of the coupling sequence).The course of the coupling curve depends on the slave position Sa and the courseof the curve in synchronized operation.The master speed must be positive, i.e. the master position must be rising.The weighting is made according to the following function:coupling curve = SK * KE + S0 * (1 – KE)with:S0 = standstill positionSK = current curve setpoint valueKA = control variable between 0 ... 1.0 (between ME and MS)Example: Change-over function over a curve cycleMSSaS TM TMSMES SSS: Slave synchronization positionSa: current slave position before start of curveME: Master coupling position = 30°MS: Master synchronized position = 340°MT: Master clock distance = 360°ST: Slave clock distanceThe slope (speed) of the coupling sequence shows a clear overspeeding incomparison with the synchronized run.
