Watlow Series 96 Temperature Controller

（2） Remote operation example

The upper computer reads the process value (register 100), set point (register 300), and alarm status (register 106) through Modbus.

Remote start curve: By writing the Modbus command register (40001=1 to start File140002=1 to start Step1).

Remote parameter modification: Write the set point to register 300 and write the PID parameter to the corresponding register (such as proportional band 500), ensuring communication write permission (non-volatile memory disable requires closing register 24).

Maintenance and troubleshooting

（1） Daily maintenance

Regular inspection: Clean the sealing ring and heat dissipation area of the front panel on a monthly basis, tighten the terminals quarterly (to avoid cold flow loosening), and calibrate the input/output annually (through the "Factory Calibration" menu, a standard signal source is required).

Parameter backup: Save commonly used parameter configurations or record key parameters (input type, PID parameters, alarm thresholds) through the "Factory Custom Menu" to avoid reconfiguration after faults.

Calibration process: Input calibration requires providing high and low point standard signals (such as thermocouple 0mV/50mV), calculating the correction value through "Electrical Input Slope/Offset", and outputting calibration in the same way (such as 4-20mA signal calibration).

（2） Common fault handling

Possible causes and solutions for the fault phenomenon

No display/output power supply not connected, fuse burned out, safety interlock activated. Check the power supply voltage and fuse (Slot C terminal 98/99), confirm the interlock switch status, and re tighten the power supply wiring

The process value deviation is large. The sensor wiring is incorrect, the calibration offset is not set, and the input type does not match. Check the sensor wiring (thermocouple positive and negative poles/RTD leads), adjust the "Calibration Offset", and confirm that the "Input Type" is consistent with the sensor

Communication failure: baud rate/address mismatch, reversed wiring, no terminal resistor added. Unify device communication parameters, check the correspondence between T+/R+and A/B terminals, and add a 120 Ω resistor at the end of the bus

The alarm cannot be cleared. The alarm condition has not been lifted and the alarm lockout confirmation process value has returned to the safe range (including the hysteresis area). Press the infinite key to clear the lockout alarm and check the "Latching" parameter setting

The curve cannot be started and has not entered the pre run mode. The step type configuration is incorrect. Press the infinite key to enter the pre run menu, select the file and step, and confirm that there is no "Jump" loop error in the curve step (such as jumping to the current step)