Slow Control State Diagram

The following poicture illustartes the Slow Control State Diagram:

The States hve the following meanings

• STOP Process is not there (exited or not yet started)
• INITIALIZED Process has set up - the process cannot assume that servers he requires are there (other then the rpm name server and smc). Only local initialization is possible. In this state the process has registered with the rpm name server. The state of the hardware is not known in this process state.
• CONFIG Process has read its configuration (e.g. from the data base system). Configuration parameters (eg the ramping speed of a power supply or the on-level high volatge) are downloaded. The actual parameters (eg the on/off setting or value of HV) are evaluated and the process state is automatically changed accordingly.
• OFF The attached hardware of the process is in a state where maintaineance is possible (i.e. HVs are off). When requested as state change the hardware is brought into that state.
• INJECTION Injection is possible and Data taking is not possible. HV might be half on (if desired). When issued as stage change request the hardware is braught into a state where injection is possible.
• ON Injection is not possible and Data taking is possible - this is the state for data taking operation with the hardware attached to the process. When issued as state change command the hardware is braught into taht state.
• ON_NOT_READY Injection is not possible and Data taking is not possible. there is no state change command to go into this state.
• ERROR process cannot recover from an error. It ether has lost his hardware (for ever) or detected an impossible situation which he cannot control anymore. In this state the process might still communicate with user interfaces for debugging. The only way out is restarting the process.

Operational remarks

Uppon setup the process will go automatically from STOP to INITIALIZED. Being in INITIALIZED means that he is there. Then the system will move synchronous through CONFIG. From there the process will start infereing his state and automatically go into the state which the hardware is in.

Malfunctioning of the Hardware ether leads to achange of state (eg from ON ionto ON_NOT_READY) or are indicated as Warnings or Alarms in the status word (like for few percent of HV channels tripped).

To start a data taking run state change requests from CONFIG-OFF-INJECTION to ON are issued synchronously. Uppon injection the system is brought back to INJECTION. ON_NOT_READY is only used form the state inference and not issued as command. Normally only transitions between INJECTION and ON are done during data taking operation.