Operation

The motor can be controlled locally and remotely. Local control is provided through the SmartStep 23 keypad controller. The keypad allows the target to be jogged into position. It also allows for small codes to be saved which will move the target ladder into preset target positions. Remote control is provided through the EPICS environment. During norml operation, target motion is controlled through the lifter MEDM GUI running on one of the computers in the Hall A counting house. The final GUI is under developemnt at this time, but it will have buttons for preset target positions, as well as lights indicating the status of the controller (i.e. any faults, at a limit, etc.). The velocity, acceleration time, deceleration time and position can also be manually set from the GUI, but the defaults should be correct for all but special situations. The position of the motor is readback on the GUI. This position is displayed in revolutions from the home position and can be compared with preset target positions.

The electronics provide a Fast Shutdown (FSD) interlock signal to the accelerator that is triggered whenever the target is moved with the beam on. This prevents damage to the target cell and ladder due to the electron beam. The FSD signal is generated by the SmartStep controller and sent to an FSD node in the Hall. Target changes require Hall A personnel to telephone MCC and request temporary masking of this FSD channel.