Festo SEC-AC-305-CO, Manual

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6. Device Control/State diagram (State machine)
6−16
Festo P.BE−SEC−AC−CO−E N en 0802a
EXAMPLE
The above mentioned example shows, what bits in the
controlword have to be set to enable the servo controller.
Now the requested state should be read out of the
statusword :
Transition from SWITCH_ON_DISABLED to
OPERATION_ENABLE:
1. Write state transition 2 into the
controlword
.
2. Wait until state READY_TO_SWITCH_ON occurs in the
statusword .
Transition 2: controlword = 0006
h
Wait until (statusword & 006F
h
) = 0021
h
1)
3. The state transitions 3 and 4 can be written combined into
the controlword.
4. Wait until the state OPERATION_ENABLE occurs in the
statusword .
Transition 3+4:controlword = 000F
h
Wait until (statusword & 006F
h
) = 0027
h
1)
Please note
The example implies, that no more bits in the controlword
are set. (For the state transitions only the bits 0..3 are
necessary).
1)
To identify a state also cleared bits have to be evaluated
(see table). Therefore the statusword has to be masked
properly.