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The D options can only be displayed. They may not be changed by the user.
The Diagnostics are not options, but rather they display internal values that are indicative of the internal state of the processor. They are useful for a serviceman or a technician and to pinpoint hardware problems and error conditions.


The D options are internal diagnostic values and may not be changed from the control panel. When a D message is displayed, press the SET key to see what the associated value is. Here is a brief explanation

D1 What the microprocessor is reading as relative temperature. This is the number that is converted to a temperature value. A 0 value indicates a disconnected temperature sensor. A number above ~ 250 indicates a shorted sensor.

D2 What the microprocessor is reading from the keys. When any of the keys is pressed, the associated number of that key is communicated to the microcontroller and displayed on the panel. A non functioning key will not cause the display to indicate it's value.

D3 What the microprocessor is sending to the relays. Each relay has an associated number. What is displayed is the sum of the numbers of all the relays that are activated, i.e. should be closed.

D4 Accumulated count of temperature errors encountered. The microcontroller keeps a running total of the number of times that a temperature error was experienced by the system.

D5 Accumulated count of hi limit errors encountered.

D6 Accumulated count of heartbeat errors encountered. The system's heartbeat is derived from the line frequency's 50/60 Hz. The real time clock, TOD, and all the controller's internal events are paced by this heartbeat. If this heartbeat becomes erratic, the system is gracefully shut down and an error is logged.

D7 The firmware revision number.

D8 The manufacturing year and week in the form yyww