SET command

To modify the parameters of a device, the command SET should be used. We will differentiate the use of the SET for three categories of devices:

• SET command for temperature controllers
  • Syntax for LTC20/21 and for LakeShore 340
  • Syntax for AVS46 (LTF)
  • Syntax for the Variox Cryostats
• SET command to set an experiment magnet
  • Setting an Experiment Magnet on GPS, DOLLY and GPD
  • Setting the superconducting magnet on LTF
• SET command for other devices

SET command for temperature controllers

Syntax for LTC20/21 and for LakeShore 340

As these temperature controllers can control different heating loops, depending on the specific setup, the parameters for both loop may be needed. The parameters are the setpoint and tolerance in Kelvin, as well as the required stability time for the temperature to be within the tolerance.

SET  <alias>|<equipment name> <control-loop 1 parameters>|<control-loop 2 parameters>

where <control-loop N parameters> = <setpoint><tolerance><stability-time>

Examples:

• Setting the main Cryostat Temperature (2-loops mode):

  SET Temperature 100.0 1.0 60 100.0 1.5 30
  

  The same action for the 2nd-port Cryostat Temperature (2-loops mode):

  SET Temperature_2nd_Port 100.0 1.0 60 100.0 1.5 30
  

  where:
  • Temperature or Temperature_2nd_Port represent the aliases for the respective temperature controller frontends,
  • 100.0 represents the new setpoint in Kelvin for the first heating loop,
  • 1.0 represents the tolerance in Kelvin for the first heating loop,
  • 60 represents the time that the first temperature needs to stay within the tolerance to be considered "in range",
  • 100.0 represents the new setpoint in Kelvin for the second heating loop,
  • 1.5 represents the tolerance in Kelvin for the second heating loop,
  • 30 represents the time that the second temperature needs to stay within the tolerance to be considered "in range".
    
    Note that the autorun sequence does NOT wait for the "in range" conditions to be fulfilled prior to go to the next autorun sequence command. If the user wants to wait for the "in range" conditions, a WAIT command (see below) has to be included as next command (or where needed).
    
    
• Setting the main Cryostat Temperature (1-loop mode):

  SET Temperature 100.0 1.0 60
  

  where:
  • Temperature represents the alias for the temperature controller frontend,
  • 100.0 represents the new setpoint in Kelvin,
  • 1.0 represents the tolerance in Kelvin,
  • 60 represents the time that the temperature needs to stay within the tolerance to be considered "in range".

Note:

Note tha the SET does solely set the parameters, but does not actually wait for the temperature to be in the defined tolerance for the defined time. To be sure to have a temperature within the tolerance, the user should also specify the command WAIT (see section Wait for reaching Device Specific Condition) after the SET command.

Syntax for AVS46 (LTF)

As the temperature control on the LTF is done in 2 steps (first without Integral parameter, then with) and as the PID parameters will depend on the mode of operation of the dilution fridge (for example with or without mixture) different parameters have to be specified in the aurorun sequence:

SET  <alias>|<equipment name> <setpoint><tolerance 1><stability-time 1>[<tolerance 2><stability-time 2>]

where <tolerance 1> and <stability-time 1> represent the tolerance in Kelvin and waiting time in seconds for the first control step (without I parameter), and <tolerance 2> and <stability-time 2 > represent the tolerance in Kelvin and waiting time in seconds for the second control step (with I parameter)

Example:

• Setting the temperature to 100 mK:

  SET Temperature 0.1 0.02 180 0.01 240
  

  where:
  • Temperature represents the alias for the temperature controller frontend,
  • 0.1 represents the new setpoint in Kelvin,
  • 0.02 represents the tolerance in Kelvin for the first control step (without I parameter),
  • 180 represents the time that the temperature needs to stay within the tolerance prior to go to the second step of the control process (in this example, the temperature has to stay 180 sec. between 0.08 and 0.12 K).
  • 0.01 represents the tolerance in Kelvin for the second control step (i.e. with I parameter),
  • 240 represents the time that the temperature needs to stay within the tolerance to be considered "in range" (in this example, the temperature has to stay 240 sec. between 0.09 and 0.11 K).
    
    Note that the autorun sequence does NOT wait for the "in range" condition to be fulfilled prior to go to the next autorun sequence command. If the user wants to wait for the "in range" conditions, a WAIT command (see below) has to be included as next command (or where needed).
    
    

Syntax for the Variox Cryostats

The GUI deltat and the MIDAS data acquisition system allow the users to control the LabView application controlling the Oxford Instrument Variox Cryostats. As explained in section Variox/Heliox Cryostat the setup has to be performed on the LabView application prior to control it from the deltat application.

SET  <alias>|<equipment name> <Variox-par.><Heliox-par.>[<NV>|A]|<Variox-par.>[<NV>|A]|<Heliox-par.>

where:

• <Variox-par.> = <setpoint><tolerance><stability-time> are the parameters for the Variox Cryostat,
• <Heliox-par.> = <setpoint><tolerance><stability-time> are the parameters for the Heliox Insert,
• <NV> is the Variox needle valve value in %. If the Variox Cryostat is in auto-needle-valve mode it will be set to manual-needle-valve mode. The option "A" will set the Variox Cryostat to auto-needle-valve mode.

Note:

• The number and type of parameters to be specified depends on the configuration of the front-end (is the Heliox or Variox setpoint requested? -- See also Section Variox/Heliox Cryostat).
• Note that the SET does solely set the parameters, but does not actually wait for the temperature to be in the defined tolerance for the defined time. To be sure to have a temperature within the tolerance, the user should also specify the command WAIT (see section Wait for reaching Device Specific Condition) after the SET command.
• To reach temperatures below 4 K, the cryostat has to be put in "Low Temperature Mode", which requires some manual operations (see manual for the Variox cryostat). Hence, autorun-sequences covering both temperature range cannot be performed in one shot.
  
  
  

SET command to set an experiment magnet

Setting an Experiment Magnet on GPS, DOLLY and GPD

SET  <alias>|<equipment name> <magnet name> <value of field in Gauss><waiting time>

Example:

SET Magnet WED 1000 60

where:

• Magnet represents the alias for the magnet controller frontend,
• WED represents the name of a specific magnet,
• 1000 represents the new field in Gauss,
• 60 represents the waiting time for the field stabilization. Note that this time is waited immediately after changing the field setpoint value. Therefore the user should choose a long enough waiting time to allow the field to stabilize.

Setting the superconducting magnet on LTF

SET  <alias>|<equipment name> <value of field in Tesla>[<mode>]

where:

• <mode> represents the mode ('P'=persistent or 'N'=non-persistent) in which the magnet will be placed.

Example:

SET Superconducting_Magnet 1.0 P

where:

• Superconducting_Magnet represents the alias for the magnet controller frontend,
• 1.0 represents the new field in Tesla,
• P specifies that the magnet has to work on persistent mode.

Note that the autorun sequence will NOT WAIT that the magnet is at field prior to process the next autorun sequence command.
To ensure that the magnet is at field prior to start a run, the command WAIT has to be invoked:

WAIT <alias>|<equipment name> ATFIELD [<max-interval>]

where:

• <max-interval> is the maximum waiting time in seconds.

Example:

SET Superconducting_Magnet 1.0 P
SET Temperature 0.5 0.02 60 0.1 240
WAIT Temperature INRANGE 3600
WAIT Superconducting_Magnet ATFIELD 3600

where: the first command sets the field (without waiting), the second command sets the temperature (without waiting), the 3rd and 4th commands wait, respectively, for the temperature to be in range and for the field to be at the setpoint. For both commands, the maximum waiting time has been specified to be 3600 s.

See also section WAIT command.

SET command for other devices

Syntax:

SET  <alias>|<equipment name> [<device specific arguments>]

Note:

Any device not being shown in the Modify Device list (except pTA and Experimental Magnets) may not be set in the autorun sequence. Use Show or Modify in the Modify Device tab to find out about currently valid Aliases, Names and Parameter Names.

The examples given below refer to the GPS aliases.

Examples:

• Setting an helium flow:

  SET Flow FLOW 2.5
  

  where:
  • Flow represents the alias for the flow controller frontend,
  • FLOW represents the parameter to be changed,
  • 2.5 represents the flow in l/min.

• Setting a sample rotation angle:

  SET Position ANGLE 130.0 30
  

  where:
  • Position represents the alias for the rotation controller frontend,
  • ANGLE represents the parameter to be changed,
  • 130.0 represents the new angle.
  • 30 represents the maximum optional waiting time for ANGLE (which should be longer than the time necessary to rotate the sample, especially if a run is started as next step).
    Note: if waiting time is not specified, the autorun sequence will wait until ANGLE is within tolerance.

• Setting a new value for the Tube Heater:

  SET Tube_Heater I 0.230
  

  where:
  • Tube_Heater represents the alias for the Tube Heater frontend,
  • I represents the parameter to be changed (here the current),
  • 0.230 represents the new current in Ampere.

• Setting a new value for a beamline element:

  SET Beamline_PiM3 FS302 400
  

  where:
  • Beamline_PiM3 represents the alias for the Beamline Controller frontend,
  • FS302 represents the element to be changed (here the slits in front of GPS),
  • 400 represents the new DAC value for this element.