Today we put in operation a new node, ITF_CONDITIONS, and we updated the already existing ITF_STATUS one. The underlying process is described in gitlab issue #19, and the main goal is to decouple what we call ITF Modes (Commissioning, Calibration, Maintenance, etc.) to ITF Conditions (Not Locked, Locking, Locked) as conditions are something the machine is doing whatever it is we want to do with it. The Conditions are:
| ITF Condition | META_ITF_CONDITIONS_index |
|---|---|
| Not Locked | 10 |
| Locking | 20 |
| Llocked | 30 |
Conditions are automatically generated by the ITF_CONDITIONS node, which only has a few states selectable; the main is DOWN, which is basically the default state, then the node will transition automatically to the three main conditions, dependently of the status of the interferometer itself, by tracking the index of the main ITF_LOCK node. The only other functionality ITF_CONDITIONS has is the Autorelock Failsafe one, which has been migrated from ITF_STATUS. This is working exactly as before, by selecting the state of the same name. The STOP state will exit from this.
Being stripped of such functionality and old unnecessary O3 code, now ITF_STATUS only deals with the modes, that have to be set manually by people, and which describe what the machine is targeted to do (or what is preventing the same thing); the modes are changed with respect to the past, and we have a few additions; each corresponds to a given node state as usual. The complete list is in the following table, and the number represents the value of the DQ_META_ITF_Mode channel (the new modes are listed in bold):
| ITF Mode | DQ_META_ITF_Mode value |
|---|---|
| Science | 1 |
| Adjusting | -1 |
| Commissioning | -3 |
| Maintenance | -4 |
| Calibration | -5 |
| Injection | -6 |
| PrepareScience | -7 |
| Earthquake | -8 |
| BadWeather | -9 |
| Upgrading | -11 |
| Troubleshooting | -12 |
| Dqstudies | -13 |
About the new modes: Earthquake and BadWeather are to be set when the machine is in some kind of trouble in locking, because we have the effects of one of the two, the second one (BadWeather) referring mostly to high wind and/or high microseismic activity.
PrepareScience is the default mode when none of the others is actually happening: this means thatif we are locking only to reach the nominal state and then take data, this is the mode. As usual, the transition to Science can be done from any state, and the node itself will take care of checking whether this is legit or not, based on the ITF_LOCK index as usual; the transition will be not even started in the case, avoiding going in and out even for a second. If for any reason we exit from Science (unlock, transition between LOW_NOISE_3 to LOW_NOISE_3_SQZ, etc), the node will automatically fall to PREPARE_SCIENCE, losing memory of the previous state, which we think is the right thing to do. After that, the mode will stay PREPARE_SCIENCE waiting for a manual operation.
To recap: Modes and Conditions are decoupled, independent information. The information Not Locked, Locking and Locked now are the (only) Conditions, and whatever was looking at them based on the DQ_META_ITF_Mode value should move to check the ITF_CONDITIONS_index instead.
The Modes are instead almost identical to the previous behaviour, and we just have three new modes.
The node graphs of the two nodes are attached.
EDIT: we temporarily reverted to the old ways, as there is some unforeseen and currently unexplained bug impacting the production of h(t), which should only look at META_ITF_LOCK_index, which wasn't affected by the aforementioned changes.
