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| Symptom | Likely Cause | Diagnostic Step | Corrective Action | |---------|--------------|------------------|-------------------| | | Power supply fault or blown fuse | Measure supply voltage at the terminal block | Replace fuse or rectify power source | | Temperature oscillates ±1 °C | PID gain too high | Open HMI → PID → Reduce Kp by 10 % | Re‑tune PID or enable auto‑tune | | Communication timeout | Network IP conflict or cable fault | Ping the device from a laptop; check switch port LEDs | Re‑assign IP address or replace Ethernet cable | | Over‑temperature shutdown | Blocked flow or sensor drift | Check flow meter; compare sensor reading with calibrated probe | Clean flow path; recalibrate or replace temperature sensor | | Fault code 0x4F | Firmware corruption | Retrieve log via USB; attempt OTA update | Re‑flash firmware using manufacturer’s utility |
April 13, 2026 Category: Industrial Controls / HVAC / Automation rhts-034
of the paper (e.g., a technical guide, a summary, or a proposal)? Who is the audience you are writing for? | Symptom | Likely Cause | Diagnostic Step
