2.3 Basic Operation2.3.1 State MachineThe servo drive uses the state machine described in the CiA DS402 standard. The state machine is operated either locally viathe LCP or remotely via the network.The state machine is operated by local signals and by the Controlword sent over the fieldbus. The state of the state machineis reported by the Statusword produced by the servo drive.A single state represents a special internal or external behavior. The state of the state machine also determines whichcommands are accepted.Illustration 2.1 shows the state machine of the servo drive with regard to control of the power electronics as a result ofcommands and internal servo drive faults.StartNot ready toswitch onSwitch ondisabledFaultFault reactionactiveReady toswitch onSwitched onOperationenabledQuick stopactive012 78 9634 516111012131514130BF157.10Illustration 2.1 DS402 State MachineThe states support the functions shown in Table 2.1. The Start state is a pseudo state indicating the start when the statemachine is activated during the start-up sequence of the device drives application software.Function Not ready toswitch onSwitch ondisabledReady toswitch on Switched on OperationenabledQuick stopactiveFaultreactionactiveFaultBrake applied, if present Yes Yes Yes Yes No No No YesLow-level power applied Yes Yes Yes Yes Yes Yes Yes YesHigh-level power applied Yes/no Yes/no Yes/no Yes Yes Yes Yes Yes/noDrive function enabled No No No No Yes Yes Yes NoConfiguration allowed Yes Yes Yes Yes Yes Yes Yes YesTable 2.1 DS402 States and Supported FunctionsQuick stop active state is implemented, which is optional according to the standard. When entering this state, the behaviorof the servo drive is according to the option code defined in object 0x605A (see chapter 7.20.6 Parameter 50-46: Quick StopOption Code (0x605A)).Servo Drive Operation Programming GuideMG36D102 Danfoss A/S © 01/2017 All rights reserved. 192 2
