Issue
In high-speed motion control applications using the Modicon M660 Controller, standard PLC logic scan times can introduce latency. This causes inaccuracies when trying to record the exact position of a moving axis or when trying to establish a precise home reference position based on a physical sensor trigger.
Resolution
Implement a TouchProbe configuration utilizing the Edge IO NTS NTSEDT0800 timestamped discrete input module in EcoStruxure Machine Expert Logic Builder. This specialized hardware captures a precise, hardware-level timestamp the exact microsecond an input changes state. By integrating this module with standard PLCopen Function Blocks MC_TouchProbe, MC_AbortTrigger and FB_HomingTouchProbe, the system can execute highly accurate position monitoring and homing sequences that are completely independent of the PLC cycle time.
Disclaimer
The views and opinions expressed in this article are those of the author(s) and do not necessarily reflect the official policy or position of Schneider Electric.
