Eliminated from:
EVS93xx-EK V8.1, EVS93xx-CK V8.1
Behaviour of the new version?
The engaging process via the CLUTCH3 function block is executed correctly. The CLUTCH3-PHOUT position output and the CLUTCH3-NSET velocity output engage at the correcot position in the CLUTCH3-PHI-SET master cycle. As a result, there is no message indicated at the CLUTCH3-ERR or CLUTCH3-DIR-ERR status output.
The new version has been equipped with code C1708/001 under which the speed tolerance can be adjusted. According to default, this code is set to 10[rpm] in order to remain completely compatible with the previous version of the CLUTCH3 function block.
What happens?
Despite the engaging command (CLUTCH3-CLOSE = TRUE) the CLUTCH3-PHOUT position output and the CLUTCH3-NSET velocity output remain in standstill state. The CLUTCH3-ERR and CLUTCH3-DIR-ERR status outputs change to TRUE.
When does the problem occur?
The problem occurs if the master value at CLUTCH3-PHI-SET is generated from an actual value signal with the typical deviations (e.g. resolver signal of the master drive) and the clutch function is disengaged. The problem appears when the engaging command is sent after the clutch function has been disengaged (CLUTCH3-CLOSE = TRUE).
This behaviour is caused by a speed tolerance window which is permanently fixed to 10[rpm] inside a function block. When the starting instant for the engaging process is determined it is precalculated to the instant when synchronous running is reached. The behaviour occurs if there are speed differences outside the tolerance at the point of time when synronous running between the CLUTCH-PHIT-SET input signal and CLUTCH3-PHOUT output signal is reached.
Possible diagnostics?
The problem can be detected in the GDC diagnostics mode: The behaviour has occurred if the engaging command has been set (CLUTCH3-CLOSE = TRUE) but the clutch remains in standstill (CLUTCH3-PHOUT = const., CLUTCH3-NSET = 0) and the CLUTCH3-ERR and CLUTCH3-DIR-ERR status outputs are set.
Short-term measures/recommendations?
Do not use master positions which are based on actual values. It is only possible to use set point-based (and correspondingly stable) values (e.g. a virtual master) as master position at CLUTCH3-PHI-SET.
Evaluation:
The function restriction makes it impossible to use the clutch function in combination with actual value based master values. Set point-based master values (e.g. a virtual master) do not cause the function restriction.
