4 CALibration Subsystem
124 U8480 Series Programming Guide
Query 
CALibration[1]:TYPE?
This query returns the current calibration mode of either “INT” or “EXT”.
Query example
Error message
This command is only able to set the calibration mode to “EXT” or “INT”. Error 
–224, “Illegal parameter value” occurs for any other value.
CAL:TYPE? Queries the calibration mode for the U8480 Series.