Corrected from:
Library: L_MC1P_MotionControlBasic (FAST Motion) V03.17.00.226
(update via Package Manager)
Response of the new version:
After mains switching the homing state will be reseted ('xIsHomed'=FALSE), in case of using an incremental TTL encoder as external position encoder for position control via the controller (PosControl-PLC).
What happens?
After mains switching, the 'xIsHomed' state mistakenly is not reset although the actual position could not be reconstructed.
When does this behaviour occur?
- An incremental TTL encoder is used as external position encoder for position control via the controller (PosControl-PLC) and
- the function for reconstructing the absolute actual position after mains switching is activated.
Which products are affected?
Library: L_MC1P_MotionControlBasic (FAST Motion)
(contained in the PLC Designer)
Short-term measures:
When using a TTL encoder as position feedback system, homing always has to be repeated for the machine after mains switching to establish the absolute reference to the machine.
Evaluation/recommendations:
Due to the operating principle of the TTL encoder, there is always a homing run required after mains switching.
If you want to use the automatic absolute actual position reconstruction function, you need an absolute-value encoder. With a simple TTL encoder, there would always occur a home position offset after mains switching. This may lead to faulty machine functions or machine damage.
