| Symptom | Likely Cause | Fix (from the XMTA-2C manual) | |---------------------------|-----------------------------------|-----------------------------------------| | | Sensor open or polarity reversed | Check wiring; reverse TC leads. | | Display shows LLL | Sensor shorted or below range | Inspect thermocouple for damage. | | Temperature unstable (oscillation) | PID values incorrect | Run auto-tune (At=1). | | Relay chatters rapidly | Cycle time (T) too short | Increase T to 20 seconds. | | PV reads wrong but sensor works | Need offset | Adjust Sc parameter (±5.0). | | Buttons do nothing | Key lock active | Set LCK = 0 . | | Heater stays ON | Output relay failed | Check relay contacts; replace unit. |
To trigger Alarm 1 when temperature exceeds 350°C:
Manual PID tuning is difficult. The XMTA-2C includes an function that calculates optimal P, I, D values.
| Code | Sensor Type | Range (°C) | |------|----------------|---------------------| | 0 | K thermocouple | -50 to +1300 | | 1 | J thermocouple | -50 to +1000 | | 2 | E thermocouple | 0 to 800 | | 3 | N thermocouple | 0 to 1300 | | 4 | T thermocouple | -200 to 400 | | 5 | R thermocouple | 0 to 1700 | | 6 | S thermocouple | 0 to 1700 | | 7 | B thermocouple | 200 to 1800 | | 10 | Pt100 (RTD) | -200 to 600 | | 11 | Cu50 (RTD) | -50 to 150 |
If your menu shows Pb , Int , dEr instead of P , I , D – that’s an RKC clone. The math is identical; only labels differ.
| Symptom | Likely Cause | Fix (from the XMTA-2C manual) | |---------------------------|-----------------------------------|-----------------------------------------| | | Sensor open or polarity reversed | Check wiring; reverse TC leads. | | Display shows LLL | Sensor shorted or below range | Inspect thermocouple for damage. | | Temperature unstable (oscillation) | PID values incorrect | Run auto-tune (At=1). | | Relay chatters rapidly | Cycle time (T) too short | Increase T to 20 seconds. | | PV reads wrong but sensor works | Need offset | Adjust Sc parameter (±5.0). | | Buttons do nothing | Key lock active | Set LCK = 0 . | | Heater stays ON | Output relay failed | Check relay contacts; replace unit. |
To trigger Alarm 1 when temperature exceeds 350°C: xmta-2c manual
Manual PID tuning is difficult. The XMTA-2C includes an function that calculates optimal P, I, D values. | Symptom | Likely Cause | Fix (from
| Code | Sensor Type | Range (°C) | |------|----------------|---------------------| | 0 | K thermocouple | -50 to +1300 | | 1 | J thermocouple | -50 to +1000 | | 2 | E thermocouple | 0 to 800 | | 3 | N thermocouple | 0 to 1300 | | 4 | T thermocouple | -200 to 400 | | 5 | R thermocouple | 0 to 1700 | | 6 | S thermocouple | 0 to 1700 | | 7 | B thermocouple | 200 to 1800 | | 10 | Pt100 (RTD) | -200 to 600 | | 11 | Cu50 (RTD) | -50 to 150 | | | Relay chatters rapidly | Cycle time
If your menu shows Pb , Int , dEr instead of P , I , D – that’s an RKC clone. The math is identical; only labels differ.
