Phoenix High Voltage Control Functions

PHENIX.ONCS.tn.24.0

June 5, 1995

The following are the functions which online controls intends to provide for high voltage control and monitoring. The function characteristics provided and the implementation of these functions will, in some cases, depend on the available hardware support which is provided by the hardware controller manufacturer. Additional functions may be provided as required for specific high voltage supply systems. As information becomes available for specific hardware configurations, the functions which will be available for each system will be provided.

Commands and Responses

  • This command will turn on and off the high voltage channel. If on the high voltage channel will return to zero. The implementation and detailed function of this command will depend on the hardware support provided by the high voltage hardware interface.

  • This comand will allow / disallow operators to set or modify setpoints to the high voltage channel.

    • This command is the desired output voltage for a single high voltage channel. The units will be in units of Kilo Volts.

  • This command will set the ramp up rate for voltage setpoints. The ability to provide ramp rates on a per channel bases will depend on the support provided by the hardware controller. The available ramp rates will be also dependent on the underlying hardware support. A software ramp can be provided for those cases where a ramp is required and it is not provided by the high voltage hardware controller.
  • This command will set high and low limits to the voltage and current setpoints available to the operators.

    • Set Voltage and Current hard limits

    This command will set the hard limits which the high voltage generator will produce. The implementation of this fucntion will depend on the available support of the hardware manufacture.

    Set Alarm Limits

    This function will set the high and low warning and severe alarm limits which are associated with every high voltage channel. The limit values will be compared to the readback voltage from the high voltage controller. An alarm will be generated if the limit values are reached. The alarm will be reported to the general on-line alarm handler.

    Set Monitor Deadband

    Each high voltage monitored value will have a monitored deadband which will determine the minimum change in value before a new value is read to be either displayed.

  • This command will provide a readback of the output voltage of a single high voltage channel. The display units will be in Kilo Volts.
  • This command will provide a readback of the output current of a single high voltage channel. The display will be in units of milliamps.
  • The returned status will depend on the functions available with the individual power supply controllers used.

    • General High Voltage System Functions

    Access Protection

    All high voltage channels will allow setpoints to be entered only by a defined user group. The purpose of this function is to prevent unauthorized modification of a subdetector system.

    Run-TimePparameter Access

  • The online group will provide the means to display the current parameters which are associated with the high voltage system. This function will provide the operator with the ability to retreive and display the current settable values which are associated with each high voltage channel. These parameters will include:

    • current voltage setpoint

    current voltage output of power supply

    ramp rates

    voltage limit values

    alarm limit values

    Read update rates

    Alarm Notification

    Each high voltage channel will have a alarm values associated with it. Alarm notification will be sent to the PHENIX on-line alarm utility. The alarm utility will provide the means to notify operators of alarm conditions. All alarms will be logged with the device name, value and a time stamp. A detailed description of the alarm utility will be provided by the online group.

    Archiving

    High voltage values will be logged periodically to the PHENIX online archiving database. High voltage values will be logged initially every 30 minutes. The voltage rate can be changed on an individual basis at at run time. The format and implementation of the PHENIX archiving facility has not been determined at this time. Details on this system will be distributed as they become available.

    It is anticipated that the log file will contain the high voltage channel name, the high voltage value in kilo volts and a time stamp at which the value was saved.

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    Ed Desmond (desmond@rsgi02.rhic.bnl.gov)