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Motion Control SW
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5.2 P(V)-Stream
For masters with NC (Numerical Control) capabilities, the software supports cyclic streaming
modes of the position and velocity, or position only. The streaming has to be strictly cyclic in
the period range 2ms to 5ms. This feature is supported with all fieldbus variants like Profibus
DP, CAN Open
, POWERLINK, EtherCAT,
Different modes are supported:
In the first mode (Motion command: 030xh) the master only streams the position.
In the second mode (Motion command: 031xh) the master streams position and velocity,
whenever possible use the PV-streaming mode, because the acceleration derivation is less
sensitive to bus jitters than in the position only streaming mode.
The third mode (Motion command: 032xh) is like the first mode, but for the derivation of the
velocity and the acceleration a configured period time (UPID 14E6h) is taken, instead of the
slave receive time stamp. This minimizes the bad influence of the transmission jitter.
The position setpoint generation in these modes is delayed 1.5 times the streaming cycle
time, e.g. with 2ms streaming period time the delay is 3ms.
In the P- streaming mode, it is possible that, depending on the cycle time, a quiet noisy
motion is generated, this because of the twice derivation of the position signal to generate
the acceleration value. In this case, it is recommended to set the position controller value “FF
Acceleration” (UPID 0x13A0 and 0x13B4) to zero.
1
P(V)-Streaming with CANOpen is only possible with transmission type 1 (synchronous transmission)
NTI AG / LinMot
User Manual Motion Control SW/ 06/12/2013
Page 67/91