The all measurement function can measure the following 29 parameters of the 
source at the same time:   
Voltage Parameters: Vmax, Vmin, Vpp, Vtop, Vbase, Vamp, Vupper, Vmid, Vlower, 
Vavg, Vrms, Overshoot, Preshoot, Period Vrms, and Variance 
Time Parameters: Period, Frequency, Rise Time, Fall Time, +Width, -Width, +Duty, 
-Duty, tVmax, and tVmin 
Other Parameters: +Rate, -Rate, Area, and Period Area.   
  The all measurement function can measure CH1, CH2, CH3, CH4, and the MATH 
channel at the same time. You can send the :MEASure:AMSource command to set 
the source of the all measurement function.   
The query returns CHAN1, CHAN2, CHAN3, CHAN4, or MATH. Multiple sources are 
separated by commas. 
:MEASure:AMSource CHANnel1,CHANnel3 /*Set the sources of the all measurement 
function to CH1 and CH3*/ 
:MEASure:AMSource?                                            /*The query returns CHAN1,CHAN3*/