Specifications

Functional Tasks, Continued
A check is made to see if the analyzer is to run a diagnostic type cycle.
This is for the purpose of validating the analytical hardware, such as
solenoid valves, detectors, carrier regulators, etc. This is optional based
on a custom application being initiated per the power fail alarm.
Cycle Control Flag
Cycle control flags are checked to see if any analyzer cycle clocks are to
be in RUN mode. If they are not, the analyzer remains in the HOLD
mode until operator intervention. If the cycle clock is in RUN mode,
based on having been in that mode prior to powering down, then that
mode should be started in progress without waiting for intervention.
The TOD (Time of Day) clock schedules events on a second, minute,
hourly, daily or weekly basis. The clock is maintained on the CAC3 board
and schedules events from the residing SYSCON database.
Event Scheduling
The TOD clock has one-second resolution that is maintained and
generated by a hardware device that maintains accurate time
independent of analyzer power. This allows a power recovery event to
determine duration of power down state.
Certain events are scheduled on a frequency basis, which are
independent of the TOD or analysis cycle clocks. The frequency clock
has a resolution of 1 second, which is used to schedule repetitive events,
such as reading DI and AI signals for alarm purposes. Scheduling of
events typically occur at a frequency of every 5 or 10 seconds. They
occur regardless of whether the analyzer is in Run or Hold.
A schedule event can be for instrument calibration and special
calibrations. Special calibrations include daily or shift averages, report
logging to a printer or Host computer. When these tasks are scheduled
by TOD clock, they are put on queue. This allows them to be performed
at the next appropriate time. Typically, this is after completion of current
analysis cycle.
Description
If a calibration is scheduled, it will be put in queue. The calibration is then
initiated after completion of current cycle and appropriate time has been
allotted for calibration blend to flow through the sampling valve. If shift
average reports are to be calculated and printed, the report should
include all cycles, which started, or sampled, during the specified shift.
To have data available for calculation, a wait period may occur for
completion of the current sample analysis.
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