1.5.7 Internal Error Shutdown Conditions

The C4 monitors system health by keeping track of three additional areas; they are:

Processor health

Tracked by watchdog timer

Memory condition

Checked at startup

Setup parameter table

Checked continuously as used

Some detected internal errors can be repaired on the fly. If this is possible, the C4 will recover from the error and you will not know the error existed. If, however, the error is not repairable and the system must be shut down, an error message will be displayed to help you understand what happened and how to prevent or cope with it. See Section 3.7.

1.5.8 Fahrenheit Temperature Scale Supported

The controller will now operate in either Celsius /C or Fahrenheit /F mode. See Section 3.4.

1.5.9 Temperature Probe Correction (Calibration)

The C4 will allow you to enter data via the Setup mode that will correct anomalies in the temperature readings and control. Such adjustments are sometimes necessary to optimize accuracy at a particular temperature, or to compensate for differences between raw probe temperature data and actual temperatures. These differences can be the result of probe placement, effects of the unit under test on the temperature data, or other causes. See Section 3.8

1.5.10“Bumpless” Temperature Control

(Not in this release. Available in next release, without charge. Check the Sigma Systems FTP or WWW site for downloadable file.)

When the setpoint is changed, the PID control algorithm begins a new “search” for the right amount of heat and/or cooling to maintain the new setpoint. Normally, for each new setpoint, the PID routines begin the search anew... behaving as if the controller was just turned on. The controller will quickly determine that heat or cooling is called for, and while the chamber or platform advances toward the new Setpoint, the PID routine adjusts for the response to heat and cool and methodically settles the chamber or platform in on the new setpoint. For most setpoint changes, where the new and old setpoints are quite different, this is a fast, accurate and appropriate method of control.

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C4 Manual Rev 7.5.2

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Sigma C4 manual Internal Error Shutdown Conditions