The Motor Scan panel allows a user to define a group of devices to be driven as a part of the scan. For each device the user can set the initial position, step size, center and final destination parameters.
Components of the Motor Scan Panel
Instrument
Mode
The user may choose between Initial/Final, Initial/Step or Center/Step modes of devices. Each mode requires the user to enter two values. Based on the entered values and a value for the number of points, the other two values for the associated device are calculated and displayed automatically. The default mode is Initial/Final.
Given values for the Initial and Final positions, value of the Center position is set at the half distance between Initial and Final. Step is calculated as the difference between Final and Initial positions divided by the number of scan points.
Given values for the Initial position and Step, the value for the Final position is set to the Initial position plus Step multiplied by the number of points. The Center is set to the Initial position plus half of Step multiplied by the number of points.
Given values for the Center position and Step, the Initial position is set to the Center minus half of the Step multiplied by the number of points. Final position is set to the Center plus half of the Step multiplied by the number of points.
Select device
This field allows the user to select which of the A1, A2, A3, A4, A5, and A6 motors to include in the motor scan. The user checks a checkbox for a device which includes it in the scan and enables its associated text fields. The user is then required to enter numeric values into initial, final, center, or step fields of the motor.
Include device
The user may choose to include another device in a scan by clicking Include Another Device button. Scan panel adds an additional device row. The user has to select the name from the drop down menu and specify the range of the desired device in the mode which was chosen at the previous step. Entered device values have to be numeric. The user may choose to remove the additional device row completely via the corresponding remove button. (Optional)
Scan Parameters
Number of points
This field specifies the number of points in the motor scan. The entered value has to be a positive integer.
Base Count
This field defines the base count parameter of the motor scan. At each point of the scan, the system will count for Base Count multiplied by Prefactor. The entered value has to be a positive integer. The default values is 1.
Prefactor
This field defines the prefactor parameter of the motor scan. At each point of the scan, the system will count for Base Count multiplied by Prefactor. The entered value has to be a positive integer. The default value of Prefactor is 1.
Data of Interest
The user selects Detector or Monitor as data of interest to be recorded when run scan is performed.
Count Against
The user can choose between Monitor or Time as the device for which Base Count multiplied by Prefactor counts are measured.
Environment
Controller type
All environment control devices installed on the server will be listed in the drop down menu. The user may choose a controller to be set during scan. Depending on the selected type of the environment controller, different set of input fields will be added to the environment subpanel. (Optional)
Temperature Controller
This device has the following parameters that the user is required to enter.
Set Point
Specifies the temperature value which will be set before the scan begins.
Tolerance
Specifies the acceptable tolerance interval around the Set Point for temperature controller.
Tolerance Band Time
Specifies how long (in minutes) the temperature must be continuously within tolerance of the Set Point, before the temperature is considered to have reached the Set Point.
Max Wait Time
Specifies the maximum time (in minutes) that the system will attempt to reach the Set Point. If it does not reach the Set Point within this timeout, the system will issue a warning message to the user and proceed with a scan. For example, if Max Wait Time set to 0, the system will give up attempting to reach the Set Point immediately and proceed with the scan.
Initial Hold Time
Specifies the delay (in minutes) between reaching the Set Point and beginning of the scan. If Max Wait Time has elapsed, the system will still hold for the specified number of minutes before proceeding with the scan. This time should to be sufficient for the whole sample to reach equilibrium.
Magnet Controller
Set Point
Specifies the magnet value which will be set before the scan begins.
Tolerance
Specifies the acceptable tolerance interval around the Set Point for magnet controller.
Initial Hold Time
Specifies the delay (in minutes) between reaching the Set Point and beginning of the scan. This time should to be sufficient for the whole sample to reach equilibrium.
Bragg Buffer
The Bragg Buffer subpanel allows the user to define a starting point of the scan in terms of hkl and energy. The panel automates the mapping of the input hkl and energy values into A1-A6 values.
Et=(Ei-Ef)
The user enters energy transfer which is the difference between initial and final energy.
Fixed Ef or Fixed Ei
The user selects which energy (initial or final) is fixed and inputs the energy value in meV units in the associated text field.
h, k, l
The user specifies hkl point.
Populate fields
By clicking this button, the user will populate the first field (initial or center, depending on the scan mode) for A1-A6 with values that correspond to the hkl and energy point specified. The user might choose to change these values afterwards. However when doing so, values for hkl and energy transfer have to be cleared from Bragg Buffer subpanel.
Scan Description
Scan name
This field gives the name the scan.
Data file prefix
In this field the user may enter data file prefix. This string will be added to the each data file name. (Optional)
Comments
The user may add comments to the motor scan. (Optional)
Controls
Clear
Clicking this button sets all text fields to their default values. Drop down combo boxes are not changed.
Dry Run
By clicking this button, the user sends a command to dry run the scan. The server calculates positions of devices for each point of the scan and sends the user a summary of device positions. After dry run is complete, the server deletes the scan description from memory.
Save
By clicking Save, the user sends a command to the server to save the scan definition. The server saves the scan in the data storage.
Save and Run
On this command, the server saves the entered scan and executes it. For each point in the scan, the server moves all scanning devices to the specified position and performs a count. After executing the scan, the server sends the user a summary of device positions and counts. Refer to Scan description for further details.