at same time? I know that you can do 2 handhelds at once. Just connect the Output high to DMM # 1 High. Connect Output low to Dmm #2 Low. Then connect DMM #1 Low to DMM # 2 High.

But is it possible to keep going and adding a 3rd, 4th, 5th DMM in series with a current source to measure current across all the DMMs at the same time?