Troubleshooting
Common Setup Problems
Most issues come from wiring, serial settings, register mapping, Wi-Fi, or cloud mode. Start with the simple checks before changing profiles.
Who this is forInstallers who flashed a gateway but are not seeing expected local or cloud data.
Before you startHave gateway power, RS485 wiring, selected profile, slave ID, baud rate, and local `/status` output ready.
Success meansThe gateway reads the controller locally and MojoScale shows recent data when cloud mode is enabled.
Modbus and wiring
No Modbus responseLikely cause: power, A/B wiring, wrong slave ID, wrong baud, or controller Modbus disabled. Check wiring first, then scan address/baud.
Wrong slave IDSymptom: every register looks dead. Check controller settings, then try common IDs such as 1, 2, 10, and 247 if appropriate.
Wrong baud rateSymptom: behaves like no device is present. Check controller serial settings. Common rates are 9600 and 19200.
RS485 A/B reversedSymptom: wiring looks correct but nothing responds. Swap A and B, then test again.
Termination or long cable issueSymptom: intermittent reads. Check cable quality, grounding, shielding, and termination for long RS485 runs.
Values look wrong
Values are blankThe gateway did not read that metric. Check function code, register address, count, data type, and selected metrics.
Values are zeroZero can be real. Compare against the controller display before treating it as a problem.
Values are 10x or 100x wrongLikely cause: scale factor. Adjust scale or decimals in the profile.
Float values look impossibleLikely cause: word order or byte order. Try the alternate 32-bit/float ordering if the profile supports it.
Wrong register baseSome manuals list 40001 while the actual address is 0. Try 0-based vs 1-based conversion.
Alarm code is numericThe profile needs a readable value map. Rename the bit or enum value so operators see the actual condition.
Wi-Fi, cloud, and local access
Gateway does not appear after flashingUse a data-capable USB cable, confirm the selected ESP32-S3 8MB/16MB target, and watch the flashing modal for errors.
Cannot connect to AP setup Wi-FiCheck the gateway is in AP-only mode, move closer, and power-cycle the gateway if the AP was just changed.
Wi-Fi credentials are wrongUse AP/local setup to update SSID and password, or reflash with corrected settings.
Cloud shows offlineCheck Wi-Fi, internet, cloud/MQTT mode, and last seen time. Local data may still work.
Local page works but cloud does notLikely Wi-Fi/internet/MQTT mode issue. Confirm the gateway is not intentionally in local-only mode.
Phone cannot open `.local`Some Android networks handle mDNS differently. Try AP address, local IP, or the cloud view if internet is available.
When to contact support
Contact support when wiring is checked, the controller model is known, the register map is available, and the gateway still cannot read useful values.