Software for the synchronization of axes - Kollmorgen

SOCAPEL SA SOFTWARE FOR SYNCHRONIZATION OF AXES 024.8068.A8.5.2 Parameters CKS, CKM, CRANS and CKMSThese parameters allow defining the ratio between the master and the slave shafts,taking into account the respective units of each.They are deduced from the formula :CKSCKM CRANS VSlave⋅ = ⋅RANMVMasterThe ratio Vslave / Vmaster is the speed ratio to be determined between the mastershaft and the slave shaft.The fraction CKS/CKM allows defining ratios containing several prime numbers suchas found in reduction gears : using decimal or binary numbers, such values could notbe expressed with absolute precision.CRANS is employed as a scale coefficient.The ratio CKS/CKM must always be 1 or less. The nearer it is to 1, the better theconversion resolution. The parameter CRANS is able to meet this criterion, since it canhave any value between 1 and 32,767.It is important for the absolute values of CKM and CKS to be as close as possible to32,767 also, for reasons of resolution. If necessary, increase CKS and CKM byapplying the same multiplication factor.The parameter CKMS is auxiliary since it expresses the same ratio as CKS and CKM :CKMS=CKS ⋅ 32768CKMIf the two shafts rotate in different directions, the negative sign of the ratio is applied tothe parameters CKS and CKMS. As for parameters CKM and CRANS, they arealways positive.RANM is neither a parameter nor a variable : it is a mnemonic expressing the scalecoefficient in the master shaft's units.In an OM/OS system, the value of RANM is defined by parameter COMOS on themaster ST1, as described in paragraph 8.11.2 below.In the OEI and second resolver systems, RANM always has a value of 256.A calculation example is given in paragraph 8.9.Special case :If the precision obtained with parameters CKS and CKM is not required (that is, aslight cumulative error is admissible), CKS and CKM can be set to zero. The ratio isthen defined by the parameters CKMS and CRANS only, according to the followingequation :CKMS VCRANSSlaveRANM32768 ⋅ = V⋅MasterThus the ratio can be adjusted while the shaft is rotating, by altering variable KMS only(which is a copy of parameter CKMS).62