Signal stretched?

Hi,

I sent a 1-second duration signal directly from AWG (1 million points in 1 MHz sampling frequency)to the scope (6403A), but I found the signal displayed on the screen is actually 1.0002 seconds (200 us more!). Do you have any explanation on this slightly stretched signal? Thanks very much.

p.s. I measured signal duration accurately by using the two cursors provided in the software.

Toni

Can you post a psdata file showing this, File->Save->CurrentWaveformOnly, we can the look at your exact setttings.