Which products are affected?
ESP-SPAC-CAM1 – Software Package Cam V1.1 (cam library LenzeCamControl1.lib)
What happens?
The master value position generated by the function block L_CamSetXAxisVelocity drifts away from the master clock pulse.
When does the problem occur?
The problem occurs if a master position is generated with master value selection as a phase difference signal via the function block L_CamSetXAxisVelocity and the x-clock pulse length has a non integer incremental value.
Possible diagnostics?
With non integer incremental values for the x-clock pulse length, the function block L_CamSetXAxisVelocity evaluates the residual value of the clock pulse length at the input dnXLengthRest. The residual value is usually calculated by the function block L_CamProfileData (output signal L_CamProfileData.ProfileValues.dnXRest) and transferred to the faulty function block L_CamSetXAxisVelocity. The problem occurs if the signal L_CamProfileData.ProfileValues.dnXRest indicates a value other than zero. It can also occur in template cam.
Short-term measures/recommendations?
If the function block L_CamSetXAxisVelocity is used ensure that only motion profiles with an integer incremental value for the x-clock-pulse length are used (e.g. by an appropriate selection of the master value-gearbox ratio and the feed constant of a virtual master).
If the 'master value gearbox ratio' and the 'feed constant' of a real master drive result in a non integer incremental value for the x-clock-pulse length you can use a transformed master axis to represent the clock-pulse length as an integer incremental value. In this case, the master speed must be adapted to the transformed master system by using a converter with remainder handling (e.g. function block L_CONV) before function block L_CamSetXAxisVelocity.
Evaluation
The error is caused in an internal calculation of the function block L_CamSetXAxisVelocity. It does not lead to a drift of the drive shaft itself, but to a faulty calculation of the current profile position. If the error occurs with feed profiles, the clock-pulse reference gets lost. Trouble-free profile mode operation and positioning is then no longer possible.
