3D magnet: update labview driver and LvDCOM for new setup

[Tom-Willemsen]

Where?

3D magnet driver (which is an LvDCOM over a manufacturer VI)

How?

Due to the failure of a temperature controller, the kit is being physically rewired to (re-)use one of the existing lakeshores for temperature monitoring and controls of some channels.

Exact details of setup changes from cryogenics group to follow.

Rob D has hacked the labview driver on LARMOR to match the state of the hardware physically. However we should implement these changes properly (in source control etc) and also update the LvDCOM as appropriate. See LabVIEW Modules\Drivers\Scientific Instruments on larmor.

This will be required before the next time the 3d magnet is used on any instrument - cryogenics are asking for this to be done by end of August.

Acceptance criteria

• SCIMAG3D labview driver & lvdcom wrapper are adjusted to match the new setup of the underlying hardware.
• Changes are tested

How to Test

verbose instructions for reviewer to test changes
(Add before making a PR)

[Tom-Willemsen]

Details from cryogenics:

The Cryo-con controller is obsolete, and the newer Cryo-con controllers seemingly use a different communication protocol.

The replacement solution is that the existing Lakeshore 336 controls both the stick and cryostat temperatures (instead of just the stick, as previously). The channel assignments will be

Channel A: Cryostat
Channel B: Stick FXD
Channel C: Stick FLT
Heater 1: Cryostat
Heater 2: Stick

Although, at the moment, the cryostat is on Channel B and Heater 2 as a way of getting us going again quickly.

Rob made a quick modification to the LabVIEW driver for the 3D magnet to make this arrangement work for the time being. > The 3D magnet is only scheduled for LARMOR this cycle, but may go to Zoom next cycle so we will need the driver looking at and getting to a state whereby it can be deployed to other instruments and used with the above channel assignment.

Would it be possible for this to be done by the end of August, giving us a couple of weeks for testing before the start of the 2022/03 cycle?

See email chain titled "3D Magnet Temperature Controller" in ISISExperimentControls mailbox for further details.

[davidkeymer]

Have had a look at edited VI using compare tool in LabVIEW. All references to the temperature controller have been removed. Do not believe this has any effect on the magnet control itself, but will need to confirm.

Also check with Cryogenics group on function of "dead" temperature controller i.e. did it have anything to do with the operation of the magnet?

UPDATE Answer from AJ:

• The "dead" temperature controller did not have any safety-related function
• There are thoughts to control the needle-valve from a heater output of the LakeShore 336. (Currently either a benchtop PSU or Galil depending whether it's used on LARMOR or ZOOM, not sure why)
• Sensor & Heater channel numbers have not been finalized

Therefore, work on this magnet system has not been completed by Cryogenics Group, and so this ticket should not be worked on until we've heard back from them. This should be early in the next shutdown.

At the very least if we are to run with how things are at the moment:

• ensure edited VI is backed up in SourceSafe
• changes made to the LVDCOM definition file to account for removal of items on VI front panel
• changes to 3D magnet OPI for same reason
• update IBEX components and configurations accordingly to take account of extra channels on LakeShore 336.
• deploy all of above to ZOOM & LARMOR in preparation
• document changes on Wiki

[JackEAllen]

For anyone picking up this ticket, if you do not have experience with LabVIEW, try and find some time to sit down with someone who does to share knowledge of LabVIEW.

[rerpha]

moving off project board as awaiting as per standup