The ShortMeasurementPort defines the port that will be the short circuit measurement port. The short circuit must be connected at the reference plane desired (typically the DUT).  

The values of this key can be 1, 2, 3, or 4 but this port must be one of the ports defined by the ThruPortPair key. In the given example the values must be either 1 or 2 and cannot be 3 or 4.

See also AMB Split Characterization.

An Example:

;*******************************************************************************
; AmbSplit configuration example
;*******************************************************************************
[AMBSPLIT_1]
CalAcquireTimeoutSec = 60
CalSetToActivate = CalSetToUseName
ConfigType = AmbSplit
DirectoryToUse = C:\Temp
Port1DevPair = ICM_FCM1:1
Port2DevPair = ICM_FCM2:1
ThruPortPair = 1:2
ShortMeasurementPort = 1
SwitchPath = ICM_SW01:1,ICM_SW02:1,ICM_SW03:1,ICM_SW04:1,ICM_SW10:0