Atul,
I wouldn't necessarily classify one of these as better or worse as far as accuracy goes. Handshaking offers you a tighter integration between the two devices.
Synchronous: The switch and dmm will share a trigger line. The dmm will take a measurement and send the signal to the switch. The switch will then send switch to the next channel in the scan list. The dmm will read the next signal after a specified time period.
Handshaking: The devices share two trigger lines now. The dmm will trigger the switch as before, but with the additional trigger line, the switch will now trigger the dmm once the proper connection has been made.
So the only real difference is in the fact that with synchronous, you have to tell the dmm to wait for a predetermi
ned amount of time, whereas handshaking will have the dmm taking data as soon as it is available. The accuracy of the measurement will not change, but the efficiency will be greater with handshaking.
And yes, the DMMs can operate using software triggers as well. NI DMM ships with an example that demonstrates this. NI Switch ships with the dmm synchronous and handshaking examples.
Hope this helps you out.
Best Regards,
Jeremy R.
National Instruments - Applications Engineer
