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To get around this we need to open the aperture cover and reset the drives. However, the logic will close the light path if this happens, which will lead to an aperture cover timeout fault. So, we temporarily force the ready bit on. This will give us time to reset the drives. Then we can disable the bypass and continue normally.

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Before bypassing

1. Ensure Aperture Cover is closed.

2. Reset GIS using front panel button.

3. Reset GIS faults using engineering screen on HMI.

4. Verify that Aperture Cover is not forced closed by the GIS.

Bypass Procedure

1. Toggle ApCover_Ready_Bypass in the EMCS PLC on.

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2. Open Aperture Cover fully.

3. Reset Aperture Cover Drives (if faulted).

4. Verify ApertureCover_Drives_RTS is on.

5. Toggle ApCover_Ready_Bypass in the EMCS PLC off.

6. Verify Comm_EMCS_to_LIC.DATA[17].3 remains on.

7. Open M1 cover normally.

8. Observe.

9. Profit.