Please help: applying H1B visa

Hi,

Due to a medical emergency in my family, I'll need to go back to china for a short period of time. I'm in H1 status now and I got an appointment in Ottawa in a few days. Anyone ever met any problem on getting H1-visa from there? Is it for sure the visa will be 2-time entry and 6 month. Thanks a lot.

Really appreciate your help.
mulan