Cycle Control Description

Chamber/Device Modes

Manual

Users configured with appropriate privilege levels will have the ability to select a manual mode for various outputs/devices EXCEPT for any devices associated with the EO subsystems. Putting a device into manual mode will require password re-entry. When a device is put in Manual mode, an event record will be logged in the database. Once manual mode is selected for a device, the user will be able to manually control the device provided interlocks are satisfied for that device. Refer to the Device Interlock SFS (2013-PR-020A-SFS-INT) for more information regarding device interlocks.

Actuators associated with the chamber heating subsystem will continue to operate normally unless they are overridden by a manual command. Any gas injection will be turned off once the pressure of 21 PSIA is reached.

Once a device has been put into manual mode, it will stay in that state unless any one of the following occurs:

  1. Device is put into Auto mode

  2. Chamber mode changes

  3. Phase changes

  4. Cycle type (i.e. sequence) changes

STOP

In stop mode all outputs are turned off. When a chamber is placed in Stop mode, an event record will be logged in the database.

Alarm 400 will be raised every [Parameter 171] seconds (General Configuration parameter) as long as the chamber remains in Stop mode and is NOT Dormant.

The following kinds of Stops are possible:

Automatic or Maintained Stop

The controller will automatically initiate and maintain the stop mode (i.e. not allow any other mode) if any of the following conditions is active:

  1. Emergency Stop (see Emergency Stop)

  2. Loss of building power (see Building Power)

  3. Chamber heating subsystem detects a problem

Manual Stop

An operator may select the stop mode at any point. The process will not continue until the cycle has been manually returned to the RUN mode.

Hold

The hold mode will cause all chamber actuators to turn off with the exception of the re-circulation blower and the chamber/jacket heat/cooling subsystem. When a chamber is placed in Hold mode, an event record will be logged in the database. If the chamber continues to remain in the hold mode for an additional configurable length of time, an alarm will sound again.

Alarm 399 will be raised every [Parameter 170] seconds (General Configuration parameter) as long as the chamber remains in Hold mode and is NOT Dormant.

The following kinds of holds are possible:

Automatic or Maintained Hold

The controller will automatically place the process on Hold when specific alarms are raised as described throughout the sections of this document.

The controller will maintain the Hold mode (i.e. not allow Run mode) if certain alarm conditions are not cleared. Stop mode will still be available if the controller is maintaining Hold mode due to certain un-cleared alarm conditions.

Manual Hold

The operator may manually place the process on Hold at any time during a cycle EXCEPT if the chamber heat subsystem has detected a problem. The process will not continue until the cycle has been manually returned to the Run mode.

Run

The run mode executes the steps of the currently selected cycle according to the active cycle sequence.

Chamber Mode Commands

Changing the chamber mode will require password re-entry. The following machine mode commands will be manually selectable by an operator:

Run Command

This command will put the chamber in Run mode provided that a maintained Hold or Stop mode is not active.

Hold Command

This command will put the chamber in Hold mode unless a Maintained Stop is active.

Stop Command

The Stop command will be available at all times and will place a chamber in Stop mode.

Abort Command

The Abort command can be requested at any time while the chamber is running a cycle except during any Air In-bleed that occurs past the Abort 1 (i.e. non-EO) abort phase. Prior to issuing an Abort command, the system will require that the user enters the current Load ID (client version 1.3.6 or later).

Once the Abort command is issued, the system will flag the process as being aborted (i.e. Run Record will indicated that the load was aborted). This command will cause the load to be processed using one of the abort cycle sequences (see description below) once the chamber is in Run mode (the cycle will jump to the next phase as per the required abort sequence regardless of what mode the chamber was in when the abort command was issued; the chamber will not automatically change the mode, however).

If the Abort command is issued and the cycle is already past the last of EO Dwell (or EO Dwell with Nitrogen Make-up), the cycle execution engine will continue to process the phases normally; the process will still be flagged as Aborted on the Run Record.

Start Command

Once a load has been successfully downloaded to control system for processing, the operator will be able to initiate execution of the cycle via the Start command as long as the following conditions are satisfied:

  1. Chamber is in dormant sequence

  2. Chamber door is closed

  3. Chamber devices must all have valid calibrations (i.e. no device calibrations on the chamber can be expired) if calibration module is present

  4. A new load has been downloaded to the controller

  5. If general configuration Keyword 28 is set to true, at least one EO drum must NOT be empty.

    1. Alarm 416 will be raised if the following conditions are met:

      1. New load is downloaded to the controller but not started AND

      2. Keyword 28 is true AND

      3. All EO drums are empty

  6. If any of the following conditions are true for either configured blower (MS-10 or MS-57) Alarm 498 (a non-manageable event configured to place the Chamber on Maintained Hold) will be raised:

    1. Mot_CD[*].FB_Fwd_DI_ref is configured but the DI is configured with a module of 0

    2. Mot_CD[*].RPM_AI_ref is configured but the AI is configured with a module of 0

    3. Both Mot_CD[*].FB_Fwd_DI_ref AND Mot_CD[*].RPM_AI_ref are not configured

The start command will initiate the normal sequence.

Start-up Checklist

If configured for your site, the Start button will present a Start-up Phase Completion window with various warnings and start-up checklist items. The cycle will not start until the user clicks the Start button on this Start-up Phase Completion window.

  • If there are warnings present, the user will have to acknowledge all warnings and then input the Load ID before being able to start the cycle

  • If all start-up checklist items are true and there are no warnings present, user will click the Start button again on the Start-up Phase Completion window to start the cycle

All the following start-up checklist items must be true to enable the Start button on the Start-up Phase Completion window:

  1. Chamber is Dormant and Running

  2. Load in the PLC has not already been started and the Load ID is not zero

  3. Chamber door(s) is/are closed

  4. Nitrogen pressure OK switch PS-28 is not detecting a problem (if exists)

  5. Steam pressure OK switch PS-30 is not detecting a problem (if exists)

  6. Instrument air pressure OK switch PS-115 is not detecting a problem (if exists)

  7. System air pressure switch PS-134 is not detecting a problem (if exists)

  8. Chamber door gaskets are sealed (if they exist)

  9. Transfer Complete signal from conveyor DI-387 is ON (if exists)

  10. If Keyword 28 is set, at least one EO drum is not empty

  11. Door is locked (if DT1-10 is installed)

  12. Minimum EO weight is available (DO-584 is ON, if exists):

  13. Chamber is not in use by Venting system (DI-395), if exists

  14. Chamber temperature is within specifications [Min/Max tolerance Parameter 3]

  15. If multiple chamber temperature sensors are configured, then the lowest chamber temperature reading is greater than or equal to the minimum temperature tolerance [Parameter 3 Min] plus the offset for phase end [Start-up equipment/phase Parameter 68]

  16. Jacket temperature is within specifications [Min/Max tolerance Parameter 7, if specified]

  17. All pressure indicators/transducers are enabled and functioning

  18. EO temperature sensors (if installed):

    1. If IT5 or IT14 then both EO temperature sensors are enabled and functioning

    2. If not IT5 or IT14 then at least one EO temperature sensor is enabled and functioning

  19. If product temperature monitoring is enabled [Keyword 10], at least one product temperature sensor is enabled and functioning

The following start-up checklist items will be a warning:

  1. If configuration parameter Check_EO_AH_Sensors_Enabled_OnStart is set for the site:

    1. All EO sensors are disabled or faulted

    2. All AH sensors are disabled or faulted

    3. If cycle is started with these warnings then the following alarms will be raised:

      1. Alarm 1007 if all EO sensors disabled or faulted

      2. Alarm 1008 if all AH sensors disabled or faulted

Cycle Sequences

Normal Sequence

In normal sequence, the cycle execution engine will follow the execution of all phases as defined in the cycle definition.

Abort Sequence 1

Abort sequence 1 will be executed when the abort command is selected for a cycle during which EO gas has NOT been injected. In this sequence, the cycle execution engine will jump to the first Vacuum phase in the final air wash sequence of the cycle definition, skipping over all other phases. All phases following this Vacuum phase will be executed normally.

Abort Sequence 2

Abort sequence 2 will be executed when the abort command is selected for a cycle during which EO gas has been injected.

If the cycle includes an EO Dwell phase:

  • The cycle execution engine will skip to the first Vacuum phase after the last of the EO Dwell phases in the cycle.

  • If the cycle does not include any EO Dwell phases, the cycle execution engine will skip to the first Vacuum phase after whichever of the following comes last in the cycle: EO Inject via Pressure/Concentration/Weight

Abort Sequence 3

Abort sequence 3 will be executed when the abort command is selected under one of the following conditions:

  1. Only Vacuum, Leak Check, and/or exhaust valves have opened since the start of the cycle OR

  2. Chamber is still in the Start-up phase

The cycle execution engine will skip to the final Air In-bleed phase.

Dormant Sequence

The dormant sequence can be initiated as follows:

  1. Operator issues Unload command while the Chamber is in Run mode and cycle is in End Phase Note: the chamber has to be in Run mode when the Unload command is issued in order for the chamber to complete the End Phase and transition into Dormant.

  2. Chamber door is opened while the cycle is in End Phase.

While the chamber is in dormant sequence, the system will maintain the jacket and chamber temperatures using the jacket temperature and chamber temperature set-point parameters (see section General Configuration (Header)).

The system will keep the Air valve BV-40 open while the chamber is Dormant as long as the chamber door(s) is/are closed.

A separate privilege role is available to allow operators to manually control equipment while the chamber is Dormant. This can be used to give certain operators this privilege in Dormant but not in any other sequence. Refer to section System Security for more information on user privileges.