Sheila, Stefan,
We debugged Daniel's Beckhoff based AS port protection logic (more on that in Sheila's alog) and updated the guardian wrapper code to work with it.
MEDM screen description (figure 1):
AS Trigger PD (top left): Is the trigger PD (ASC-AS_C_SUM), as seen by Beckhoff within alowable power limits (i.e. there is power on the PD, but also not too much)
AS Trigger Logic (bottom left): Control of the fast trigger logic - feeds into the fast shutter and into the PZT shutter. (Note: manually closing this trigger actually fires the fast shutter.)
Fast Shutter (top middle): Control of the fast shutter (Note: manually closing the shutter here closes the fast shutter SLOWLY.)
PZT Shutter (bottom mddle): Readbacks for the PZT shutter.
Protection (right): Logic and readback for the shutter status and testing.
The protection implements Daniels ECR E1600248 testing. More on that in SHeila's alog.
Note that the Beckhoff code cannot check the light on PDs downstream of the shutter. We indend to add a check of the downstream diodes into the FAST_SHUTTER guardian.
FAST_SHUTTER guardian:
This guardian is intended to implement the rest of ECR E1600248. Currently, it checks whether the AS_PORT_PROTECTION needs a test (Beckhoff readback), runs that test by poking Beckhoff if needed, and verifies that all the light levels are adequate before going to READY.
If any of the conditions are not met, it stops in SHUTTER_FAILURE and waits for human action.
The ISC_LOCK guardian will be updated to require the FAST_SHUTTER guardian to be ready before proceeding to full lock.
Items of ECR E1600248 still to be implemented:
1) Automatic check on lock-loss that the shutter worked as intended. If not, command PROTECTION_AS into Fault, and raise audio warning. This part however can only be implemented when seeing real lock-losses. So we intend to initially require a human to look at every lock-loss - the corresponding medm button is implemented - see alog 29001.
2) Augment the FAST_SHUTTER guardian to monitor the photodiode levels during the Beckhoff testing, and require that the downstream light is cut off and doesn't come back.
Sheila, Patrick, Stefan, Jenne
We made several changes today both in Beckhoff and the FAST_SHUTTER guardian the course of checking the bechoff code that tests the fast shutter.
First,we spent some time on the beckhoff code that Daniel wrote that is intended to be used as a periodic check (to be run at the next lockloss once it has been 48 hours since it has been run.) The state machine which is run if someone clicks on the run button here
- checks that things are ready for the shutters to be triggered and then triggers them by closing SHUTTER_G controller (this triggers the fast shutter)
- half a second latter checks that both shutters are closed
- 9 seconds later requests the shutters to open again (once they are ready)
- checks that they are reopened and ready to be triggered again.
We had to make several changes to the original code to get this going, the current version which we have tested several times is committed as rev 3067:
- Changes to timing so that we waited long enough for the shutters to close but not so long that they got reset, ect.
- We created a new epics variable FAULTTYPE which tells you which part of the test failed if the test failed. This was to help us debug and will probably be usefull in the future.
- We removed the second close comand that was in the code because we believe that we want the test to end with the shutters open and ready if everything is OK
- We had to separate the check that the shutters had closed from the request to reopen them.
- The reopen command had to be sent to the fast shutter, not SHUTTER G as was done before, which meant we had to add this as a arguement to the test function block.
As we made these changes we had several unexplained difficulties with beckhoff restarts.
This is intended to be integrated into guardian, so next we we decided to separate the two functions of the FAST_SHUTTER guardian as Jenne had written it into two different nodes, one which will be managed by ISC_LOCK and tests the fast shutter after DRMI has locked and one which will not be managed by ISC_LOCK but will check that the fast shutter has triggered after a lockloss with sigiificant power in the arms. Separating these two things makes it significantly easier to write both in the way we want. The FAST_SHUTTER guardian is currrently tested and is the one which manages the beckhoff tests. The tested version is revision 14023.
