Danfoss VLT Series Programming Manual page 21

Servo Drive Operation
2.3 Basic Operation
2.3.1 State Machine
The servo drive uses the state machine described in the CiA DS402 standard. The state machine is operated either locally via
the 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 machine
is 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 which
commands are accepted.
Illustration 2.1 shows the state machine of the servo drive with regard to control of the power electronics as a result of
commands and internal servo drive faults.
Start
Not ready to
switch on
Switch on
disabled
2
Ready to
10
switch on
12
3
Switched on
4
16
Quick stop Operation
active enabled
11
Illustration 2.1 DS402 State Machine
The states support the functions shown in Table 2.1. The Start state is a pseudo state indicating the start when the state
machine is activated during the start-up sequence of the device drives application software.
Function
Not ready to
switch on
Brake applied, if present
Low-level power applied
High-level power applied Yes/no
Drive function enabled
Configuration allowed
Table 2.1 DS402 States and Supported Functions
Quick stop active state is implemented, which is optional according to the standard. When entering this state, the behavior
of the servo drive is according to the option code defined in object 0x605A (see chapter 7.20.6 Parameter 50-46: Quick Stop
Option Code (0x605A)).
MG36D102
Programming Guide
0
1
15
Fault
7
14
13
Fault reaction
active
6
8 9
5
Switch on Ready to
disabled switch on
Yes Yes Yes
Yes Yes Yes
Yes/no Yes/no
No No No
Yes Yes Yes
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Operation Quick stop
Switched on
enabled
Yes No
Yes Yes
Yes Yes
No Yes
Yes Yes
Fault
reaction Fault
active
active
No No Yes
Yes Yes Yes
Yes Yes Yes/no
Yes Yes No
Yes Yes Yes
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