Guidance on Writing Scripts for the Muon Front End

This page contains guidance on writing scripts for the Muon Front-End control PC (NDEMUONFE). The information on this page is specific to NDEMUONFE and is not relevant to other control PCs.

Contents

• Starting & Stopping Runs Remotely
  • Ensuring the control machine has sufficient permission to begin a run
  • Using the script to control the runs
• Using Blocks to Write Tuning Control Scripts
• How to alter write access to blocks for each instrument
• How to Re-apply Settings

Starting & Stopping Runs Remotely

Ensuring the control machine has sufficient permission to begin a run

The relevant code can be found in the github repository:

https://github.com/ISISComputingGroup/mfe_control_scripts

The code is written in Python and relies on the win32com module. Please ensure this module is installed before running.

There is a file, run_interactively.py, which can be used to trigger commands on multiple machines interactively. It is currently set up to run on the 3 MFE instrument PCs. You can adjust it by changing the list of machine names in the variable MACHINES. To run just launch the script with Python.

Note that the script relies on the host machine and user having sufficient DCOM permissions to talk to the three instrument machines which can be achieved through the Windows credential manager.

1. Go to the start menu
2. Type "Credential Manager" and open the Credential Manager
3. You will need the credentials for all the machines you want to connect too. The "Persistence" field for the credentials must be "Enterprise" or higher (not "Local machine").

4. To add a new credential

   1. Click "Add a Windows credential"
   2. Enter the credentials (e.g. NDXMUSR, NDXMUSR\spudulike, [PASSWORD])
   3. Click "OK"

Using the script to control the runs

To write your scripts, use the MultipleDaeController class in Python to issue commands to multiple machines simultaneously. The script run_interactively.py provides a good example of how to use it.

from multiple_dae_controller import MultipleDaeController
controller = MultipleDaeController()
waitfor_seconds = 10
for m in ["NDXHIFI","NDXMUSR","NDXEMU"]:
    controller.add_machine(m,waitfor_seconds)
controller.run_on_all("get_run_state")
controller.run_on_machines("end",["NDXHIFI","NDXMUSR"])
controller.run_on_machine("begin","NDXEMU")

The following methods are currently supported:

• begin
• end
• pause
• resume
• abort
• get_run_state
• get_events
• get_frames
• get_counts
• waitfor_counts
• waitfor_frames
• waitfor_events

Using Blocks to Write Tuning Control Scripts

A configuration with blocks should be created as for any IBEX instrument on NDEMUONFE.

On an appropriate system, import genie_python to Mantid, and set your instrument to be "MUONFE", then get the associated blocks.

set_instrument("MUONFE")
get_blocks()

You should now get a list of blocks on the remote system. These can then be used as standard for scripting by writing to and from those values.

Return to Contents.

How to alter write access to blocks for each instrument

The initial gateway setup has been undertaken. Should the computers being provided control need to be changed, then the gateway should be restarted at the very least, and it would be wise to consider restarting the whole server.

For any system in R55 which requires full control of all aspects of NDEMUONFE ensure that there is an entry in globals.txt on NDEMUONFE of the format

ACF_IH1=computer_name

You can specify up to four of these.

Gateway settings have been set up to allow NDX and NDL systems to control each instrument respectively (so the items used by MUSR have write access from MUSR). There are more detailed instructions on how to set up these aspects of the gateway in:

https://github.com/ISISComputingGroup/ibex_developers_manual/wiki/Access-Gateway

Machines listed in the globals.txt can be restricted to read-only access by sending the following command:

caput IN:MUONFE:CS:EXCLUSIVE 1

There is a similar PV for each instrument, so to limit HIFI to read-only:

caput IN:MUONFE:CS:EXCLUSIVE:HIFI 1

Or to allow for writing to the EMU values:

caput IN:MUONFE:CS:EXCLUSIVE:EMU 0

How to Re-apply Settings

IOCs controlling Power Supply Units (PSUs) have the option to re-apply their set-points (current, voltage, status on/off) the next time they are restarted. The following may be useful if, for any reason, the PSUs are restarted and lose their set-points, and you need a quick way to re-apply them all at once rather than manually one by one.

The relevant configuration must be set up in the following way:

1. Open the Edit Configuration dialog (by selecting Configurations > Edit from the Configuration menu).
2. In the IOCs tab, locate the correct IOC and make sure both the Auto-start? and Auto-restart? boxes for the IOC are checked.
3. In the IOC Macros tab, select the correct IOC and set the macro SP_AT_STARTUP to YES (default is NO).

The set-points can be re-applied by reloading the current configuration (which will restart the IOCs), with the following genie_python command:

reload_current_config()

Note that the set-points can also be re-applied by restarting the IOCs individually in the IBEX GUI (as long as the SP_AT_STARTUP macro is set as above).