Fieldbus control through a fieldbus adapter 409 ReferencesReferences are 16-bit words containing a sign bit and a 15-bit integer. A negativereference (indicating reversed direction of rotation) is formed by calculating the two’scomplement from the corresponding positive reference.ABB drives can receive control information from multiple sources including analogand digital inputs, the drive control panel and a fieldbus adapter module. In order tohave the drive controlled through the fieldbus, the module must be defined as thesource for control information such as reference. This is done using the sourceselection parameters in groups 22 Speed reference selection, 26 Torque referencechain and 28 Frequency reference chain.Debugging the network wordsIf parameter 50.12 FBA A debug mode is set to Fast or Normal, the referencesreceived from the fieldbus are displayed by 50.14 FBA A reference 1 and 50.15 FBAA reference 2.Scaling of referencesThe references are scaled as defined by parameters 46.01…46.04; which scaling isin use depends on the setting of 50.04 FBA A ref1 type and 50.05 FBA A ref2 type.The scaled references are shown by parameters 03.05 FB A reference 1 and 03.06FB A reference 2.46.01 (with speed reference)46.02 (with frequency reference)0-2000020000DriveFieldbus010000-1000046.03 (with torque reference)-(46.01) (with speed reference)-(46.02) (with frequency reference)-(46.03) (with torque reference)
