Festo CiA 402 Manual page 120

6 Operating modes
In Fig. 6.16, a new positioning task is only started after the previous one has been completely finished.
To determine this, the host evaluates the bit target_reached in the object statusword.
Velocity
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2
v
1
t
0
Fig. 6.16 Simple positioning task
In Fig. 6.17, a new positioning task is already started while the previous one is still in process. The host
already passes the subsequent target on to the motor controller when the motor controller signals with
deletion of the bit set_point_acknowledge that it has read the buffer and started the related position-
ing task. In this way, positioning tasks follow each other seamlessly. For this operating mode, the object
end_velocity should be written with the same value as the object profile_velocity so that the motor
controller does not briefly brake to 0 rpm each time between the individual positioning tasks.
Velocity
v
2
v
1
t
0
Fig. 6.17 Continuous sequence of positioning tasks
If, besides the bit new_set_point, the bit change_set_immediately is also set to "1" in the controlword,
the host instructs the motor controller to start the new positioning task immediately. In this case, a
positioning task already in process is interrupted.
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t t
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Festo – GDCP-CMMS/D-C-CO-EN – 1404NH – English
Time
t
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Time
t
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