Collimator Functional Diagnostic Tests

1.1 Liquid Bearing Tube ONLY

Open command window and execute “rotor_ctrl –start” command before the procedure execution. Refer to Rotor Control Tool for LB Tube (VCT)

1. On the console select the DIAGNOSTICS tab in the Common Service Desktop.
2. Launch the COLLIMATOR FUNCTIONAL tool. Refer to Figure 1 for the layout of the tool interface.
3. Select the functional test desired in the Test Selection drop-down box indicated in Figure 1. The different tools are described in the following sections.

   Figure 1. Collimator Functional Application Position Test GUI

   

This test positions the Cams and filter to the selected positions for the entered test duration. Refer to Figure 1for the layout of the tool interface.

1. The test runs in continuous modes which help detect intermittent operating conditions.
2. The test provides a means to visually validate the aperture and filter positions
3. This test can be used to confirm the functional operation of the collimator.

1. Look for highlighted fields that indicate the cam or filter did not make it to position.
2. Check the log for additional information when this occurs.

1. Watch for finger pinch hazards.
2. Attempt to move the filter and/or cams, when test is complete, and verify motor has holding torque.

1. This test will verify that no mechanical binding is present.
2. The manual mode can be used for signal tracing.
3. You check for motion when errors indicate no motion sensed.

If the display does not indicate changes in the encoder count, visually check the filter for motion:

1. If filter is moving, failure is in the encode circuit
2. If filter is not moving, failure is in the drive circuit.

1. Watch for finger pinch hazards.
2. The filter drive can be divided into two functions as shown in Figure 3

   • Motor Drive (Positioning driver)

   • Encoder (Position feedback)

   Figure 3. Collimator Filter Position

   

This test reads and displays the CAM and filter encoder counts while the devices are positioned by hand. Refer to Illustration 4 for the layout of the tool interface.

1. When (to use)

   This test can confirm an encoder problem.

2. What (to look for)

   Verify encoder reading changes once the cams or filters are moved.

3. Notes

   • Watch for finger pinch hazards.

   • The test reduces the cam holding torque to allow the cams to be rotated by hand.

   • Cams are 2000 counts per rotation.

   • Filter is 1000 counts per rotation.

   • If the cam encoder fails the whole collimator assembly should be replaced.

   Figure 4. Collimator Functional Encoder Test GUI

   

1. This test can verify that no mechanical binding is present.
2. The manual mode can be used for signal tracing.

1. If the display does not indicate changes in the encoder count, visually check the CAM for motion.
2. Listen for mechanical vibration or binding.

1. Watch for finger pinch hazards.
2. CAM A and B circuitry is the same.
3. CAM operation can be divided into two functions as shown in Figure 6:

   • Motor and drive

   • Encoder

   Figure 6. Collimator CAM Rotation

   

No finalization steps.