Lakeshore Learning Materials 622 User Manual
Page 55
Lake Shore Model 620/622/623/647 Magnet Power Supply User’s Manual
Remote Operation
4-17
4.3.6
Computed Field Commands Description
The MPS can also display Computed Field rather than current. This is useful with Superconducting magnets
because there is a linear relationship between the current and actual field to a reasonable degree of accuracy.
This feature is not to be confused with the field as measured with the Model 6226 Liquid Helium Level and
Gaussmeter Input Card. The commands and queries below allow users to calculate the same Computed field
in the host computer as is displayed on the MPS front panel.
CFPA
Programs Computed Field/Ampere Constant
Input:
CFPA [field/ampere] where field/ampere is kG/ampere or tesla/ampere dependent on the
computed field units.
Remarks: Programs the kG/ampere or tesla/ampere constant used primarily in superconducting
magnets. Limited to 9.999 kG/ampere (0.9999 tesla). Value is rounded to 0.001 kG/ampere or
0.0001 tesla/ampere. Be aware of MPS units via the CFUNI? query so as not to be in error by
a factor of 10.
CFPA?
Computed Field/Ampere Constant Query
Input:
CFPA?
Returned: A number between 0 and 9.999 kG/ampere or 0.9999 tesla/ampere
Remarks: Query units with CFUNI? to verify correct units. Returns 5 character plus up to 2 terminators.
CFUNI
Program Computed Field Display Units
Input:
CFUNI [Units] where Units = K displays kG, Units = T displays tesla.
Remarks: Enable computed field status with CFPS to display computed field.
CFUNI?
Computed Field Units Query
Input:
CFUNI?
Returned: Returns K if units = kG, T if units = tesla.
Remarks: Returns 1 character plus up to 2 terminators.
CFPS
Set Computed Field Display Status
Input:
CFPA [Status] where Status = 0 displays amperes, Status = 1 displays Computed Field.
Remarks: The computed field = kG or tesla based on the CFUNI units.
CFPS?
Computed Field Status Query
Input:
CFPA?
Returned: 0 = amperes currently displayed, 1 = Computed Field currently displayed.
Remarks: Returns 1 character plus up to 2 terminators.