RO (output impedance) is setting 25Ω, the setup value of AC 
voltage is {0.01~1|MAXimum|MINimum}.
 
Set syntax 
:MEASure:VOLTage:AC 1 
:MEASure:VOLTage:AC 1M 
:MEASure:VOLTage:AC 1MV 
:MEASure:VOLTage:AC 1E-3 
:MEASure:VOLTage:AC MAXimum 
:MEASure:VOLTage:AC MINimum 
Query syntax
 :MEASure:VOLTage:AC? 
Return data 1.000000E+00 (Format is in <NR3>) 
When the Level setup is current mode, the data returns 9.9E37.  
 
Description: 
Set parameter When RO(output impedance) is setting 100Ω, the 
setup value of AC current is {0.0002~0.02|MAXimum|MINimum}. 
When RO (output impedance) is setting 25Ω, the setup value of AC 
current is {0.0002~0.04|MAXimum|MINimum}.
 
Set syntax
 :MEASure:CURRent:AC 0.01 
:MEASure:CURRent:AC 10M 
:MEASure:CURRent:AC 10MA 
:MEASure:CURRent:AC 1E-2 
:MEASure:CURRent:AC MAXimum 
:MEASure:CURRent:ACMINimum 
Query syntax
 :MEASure:CURRent:AC? 
Return data 1.000000E-02 (Format is in <NR3>) 
When the Level setup is voltage mode, the data returns 9.9E37.