add error handling

Initial Commit:
clr.AddReference("address of dll")
from I8Devices import Device
myDevice = Device()
myDevice.ConnectToDevice()
myDevice.StartDataAcquisition()
cntx = 0
datach1 = []
while cntx < 20000:
    data = myDevice.get_data()
    cntx+=1
    datach1.append(data[0])
myDevice.StoptDataAcquisition()