Remote Operation

1. Make sure the power is on to the Oven Heater Controller Chassis as described above. Also verify the alarm set points for the oven air flow and heater temperature as above.
2. Verify the current temperature of the oven. It is shown on the GUI on the blue HacOMEGA_RTD readback. It's shown on the meter and also in the readback box. Also, a plot of oven temperature vs time is shown on the stripchart in the bottom-left of the GUI (labelled oven temperature). The units are $^\circ$C. The value should be reasonable, e.g. around room temperature if the oven has been off for several hours or more. If the value does not make sense, either the controller is misconfigured (see directions for manual control above) or the RTD in the oven is broken or incorrectly connected. Do not proceed before you have a sensible reading.
3. Verify that air is flowing. The air flow readout should indicate a value of 350-450. These are arbitrary units. As long as the heater is off, the reading should not fluctuate by more than about $\pm 10$ units.
4. Verify the current temperature of the heater. It should be close to room temperature. If the value is unreasonable, either the readout is misconfigured or the thermocouple is broken. Do not proceed before the problem is corrected.
5. Verify that alarms are reset. The alarms are reset by pressing the ``Reset'' button in the upper-left of the GUI.
6. Begin heating. To avoid damage to the oven, the temperature must be increased to the final value slowly. A good final operating temperature is 170$^\circ$C, and a good ramping rate is 60$^\circ$C/h, i.e. heating of the oven will take about three hours to complete.

   In controlling the Oven Temperature from the GUI, you must enter a new temperature setpoint by hand at fixed time intervals. Enter the desired setpoint in the ``SP1'' enter box in the lower right of the GUI. You should increase the value by 10$^\circ$C every 10 minutes. For example, if the current oven temperature is 35$^\circ$C, start with a setpoint of 45$^\circ$C and increase this value by 10$^\circ$C in approximately 10 minute intervals. The heater is controlled in PID (proportional, integral, derivative) mode. It approaches the setpoint according to the PID parameters defined in the ``Prop. Band'', ``Reset'' and ``Rate'' boxes in the lower-right of the GUI. These values can be changed, but the defaults should be fine except for special circumstances.

7. Check stability of the final temperature. The temperature might overshoot slightly. If the overshoot is less than about 5$^\circ$C then this is normal. If the stability is poor it is probably due to incorrectly set PID parameters on the GUI. Changing these parameters is best done by an expert since this requires in-depth understanding of the system.

   The laser contributes significantly to the heating of the oven. Therefore, you will notice sudden temperature instabilities when the laser is turned off or on. It will take several minutes for the controller to compensate for such changes.

8. The air flow rate is slightly dependent on the heater power applied (conductance varies with temperature). Therefore, the flow rate will fluctuate by some 10-20%. This is normal.

9. At any time you can place the controller in standby mode by pressing the ``Standby'' button in the upper-left of the GUI. This will turn the heater off completely and can be used when the system appears to malfunction. However, exercise some caution if the oven is at an elevated temperature since it will quickly cool down if heater power is disabled and you will lose time bringing it back up to operating temperature.

10. In an emergency, simply turn the power to the chassis off completely. This will open the interlock loops, thereby cutting power to the heater and placing the laser in standby mode.