Finding the root cause of an erratic signal can feel like chasing a ghost, especially when your trend lines show noise that shouldn't be there. In this session, we walk through a real-world troubleshooting scenario involving a Yamaha robot simulation where the A3 axis exhibited mysterious spikes. While it initially looked like signal noise or a math error in Studio 5000, the investigation led deep into the interaction between the PLC and the Ignition SCADA system. We explore why a standard cross-reference in the PLC didn't reveal the culprit and how switching to read-only communications finally exposed a hidden bidirectional tag write.

We also discuss the common trap of "patching" problems with software filters instead of identifying the source. Whether it is a bad shield on an analog line or an accidental setting in your HMI, understanding the "why" behind the spike is what separates a technician from a parts changer. Additionally, we touch on the challenges of modern Ethernet troubleshooting, the limitations of Wireshark without port mirroring, and why the "View Diagnostics" tool in Ignition is a game-changer for identifying communication conflicts.

Helping you become a better technician so you will always be in demand

Not sure what video to watch next? Enhance your skills and track your progress at https://controls.tw/yt-courses!

Items used in this video:PLC Trainer https://controls.tw/yt-plc-trainers

The above links make these videos possible. Please use them!