Disconnecting issue with Firewire ports on macbook pro

I am using macbook pro and i have purchased Lacie rugged 500Gb. The problem is that when i am trying to connect Lacie rugged 500Gb with the help of firewire, then it gets connected for that time and after some time it suddenly looses the connection. I don't have any idea why i am facing this issue. If you have any solution related with this issue, then try to help me out.

I will advise you to try a different FireWire 800 cable and then try to connect it with Lacie rugged 500Gb hard disk. I think that doing this might help you in solving your problem as there might be some problem with your cable. So try this out and accordingly send me your reply.

I have solution for this problem so i will suggest you to try and do the following things.

1. First go to System Preferences in macbook.
2. Then go to Energy Saver.
3. Here you have to make sure that you have unchecked the option of "putting the hard drive to sleep whenever possible".
4. Once you are done with this now try to connect your hard drive with your macbook.

Hope it helps to you.

Thanks for your reply. I have tried the solution given by and was successfully able to solve my issue. Now my hard drive does not get disconnected and it is running without any issue. So i would like to thank you for you kind support and also for spending you precious time in helping me.