Siemens Maxum II Manual page 11

Self Test
After the self-test, the following conditions occur:
● Installed hardware is initialized.
● Interrupts are enabled.
● Oven temperatures and carrier pressure default set points are output.
● Analog input system(s), associated with detector inputs, are initialized and begin scanning.
The System Controller (SYSCON) verifies that a valid database is resident, then ouputs the
appropriate temperature and carrier set points. If a valid database is not verified, default set
points are left in place.
Oven Temperature
The analyzer monitors the oven temperature to ensure that it has stabilized at the set point
before automatically proceeding. Depending on how long primary AC power has been off, this
may take from 2 seconds to 45 minutes.
Cycle Control Flag
Cycle Control Flags can be used to run optional diagnostic cycles to validate analytical
hardware including solenoid valves, detectors, or carrier regulators. This option is typically
based on a custom application being initiated by a power-fail alarm.
Cycle Ccontrol Flags indicate 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 RUN mode prior to powering down, then RUN mode
starts in progress without waiting for intervention.
Program Event Scheduling
The Time of Day (TOD) clock schedules events on a second, minute, hourly, daily or weekly
basis. The clock is maintained on the system controller and schedules events from the residing
SYSCON database.
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 frequency events can be set to 5 seconds or greater. They occur regardless of whether the
analyzer is in Run or Hold.
Description
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 the TOD clock, they are put into queue. This allows them to be performed
at the next appropriate time. Typically, this is after completion of current analysis cycle.
Maxum edition II Analyzer General Maintenance
Manual, August 2018, A5E42019842001
System Functions
3.2 Functions
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