How much memory does your scope have? Four channels at 40MHz for one second is 4 * 40M * 1 * 2byte/sample = 320MBytes. Unless you have the highest memory option (512MBytes), you will not be able to store it all in the scope's memory. If you have the medium memory option, you may be able to get the job done by streaming data from your device as you take it, although even that will be iffy (PCI bandwidth is practically about 100MBytes/sec or less, depending on system load). Options are to drop your acquisition rate or your time length, neither necessarily good. You may be able to drop your resolution from 2 bytes to one, but it has been so long since I used the NI-SCOPE driver and I have never used the 5105 that I don't know if this is even possible. This would only work if you have the 256MByte memory option.
