14 C4 Manual Rev 7.5.2
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.