Software for the synchronization of axes - Kollmorgen

SOCAPEL SA SOFTWARE FOR SYNCHRONIZATION OF AXES 024.8068.A8.11 REFERENCE TRANSDUCER8.11.1 PrincipleOne ST1 motion controller can transmit references to other ST1's, and thus becomesthe "master shaft" of the latter, as defined above (particularly in paragraph 8.5).Such a system requires fitting the ST1 with an OM ("optional master") board. Thesoftware transmits a given reference to this board in parallel form; the board convertsthe reference into serial format and transmits it down an optical fiber to the slaves, inthe particular format required. An OS ("optional slave") board at each slave transformsthe serial code into parallel data, read by a processor in each slave amplifier. Serialdata are transmitted at a rate of 3000 values per second. A new reference (24 usefulbits) is transmitted in each TU.The software (V0500 family) configuration allows a given ST1 to act as both slave to amaster, and master to other slaves. Nevertheless, since the ST1 can accommodateonly one optional board, this configuration is possible only if the first master shaft isfitted with a resolver.Master shaftRResolverOMST1OSST1MMFigure 8.13The reference transmitted in such a system can be produced by various variables,such as :VIREFVMUSVIRset-value for speedtranslated master speedactual speedCOCOU torque reference produced at slave outputThe selection is made in the parameter COMOS.Transmission of the actual speed is not recommended, since it contains interferenceas well as feedback error. In addition, resolution is more coarse than for the referencespeed, and is insufficient to allow the slave to deduce an acceleration component forits feed-forward command. Finally, the slaving precision between master and slave isnot better. Thus this mode is only justified if the control error on the master shaft canbe very great : there will be less control of the slave shaft but the latter will be coupledmore closely with the master.82