CVS external firewire drive?

[kolachalama]

Hello Everybody,

Thanks for the help.

Anna

[SebastiaanNL]

Hello,

I'm trying to connect a FireWire Hard Drive to my PXI system using the PXI 8252 card. I followed all the steps in the NI-1394 External Drive Support Tutorial, but the PXI system still does not recognize the drive. The Drive is Formatted in FAT32 and NI-1394 External Drive Support 1.4.1.3.0 is installed on the PXI. Either using FTP or the LabVIEW File I/O primitives, I can't seem to find the drive. Also when I run the NI-1394 External Drive Enumeration Example on the PXI system with the FireWire drive connected to system, it doesn't find the drive.

On the PXI system (PXI 8186) I'm running Labview RT 8.5 and also the OHCI Compliant IEEE 1394 Host Controller work perfectly, other FireWire products have no problem working with the PXI system.

I've formatted the FireWire drive in every imagineble way (extended partition, primary partition, a lot of diffirent clustersizes, all in FAT32), but none seem work. I've checked the datasheet of the FireWire drive (LaCie Rugged 160 GB, but it was formatted to 32 GB because of FAT32) and the drive is OHCI compliiant and SBP-2 compatible, as far as I understand. I haven't tried a diffirent drive yet, because I've none availible.

Hopefully, somebody can help me with this problem.

Regards, Sebastiaan.

[BruceAmmons]

I once ran into problems with formatting a hard drive for a realtime PC.  I found that if I created a partition larger than 8 GB, it would not recognize the drive.  You might want to try creating a partition 8 GB or smaller and see if that works.

Bruce

[SebastiaanNL]

Thanks for your reply, Bruce.

I just tried a format of 7.8 GB on my hard drive. Unfortunately, the the PXI system still doesn't recognise it.

I'm using this hard drive: http://www.lacie.com/products/product.htm?pid=10722

I'm thinking it just isn't compatible with a PXI because of wrong chipset on the harddrive. Is there anybody here who has some experiance with connecting a FireWire harddrive to a real time PXI system?

Regards, Sebastiaan.

[Steve Penney]

Hi Sebastiaan,

Very silly question and you've probably tried it already - are you relying only on the bus power from the firewire port to power the hard drive? It could be that either the firewire cable is too long or that for some reason the Realtime OS doesn't allow you to pull power off the firewire card or that the firewire card is not able to supply enough power for the hard drive. It could be that there is just enough power there to get the light on the drive to work, but not enough to spin the disk up. You could try using the additional USB-power cable that comes with these drives to supply additional power (try from one of the USB ports on your PXI controller and if that doesn't work try to use a USB port from another PC or laptop). You could also use a standard 5V DC power supply with the correct size adapter if you need to.

Something else - have you tried using the hard drive in one of the USB ports in your PXI8186 controller just to see if it is detected?

Kind regards,
Steven Penney

[SebastiaanNL]

Hi Steven,

I'm sure that it isn't a power problem. I can feel and hear the drive spinning up when I connect it to the PXI in the same way it spins up when I connect it to a PC. Even when I connect it to the USB port of the PXI the drive isn't recognized. Even though, thanks for your reply.

Somebody has an idea?

Regards, Sebastiaan.

[VGA_CD-ROM]

Hi Sebastiann,
I tried to look into power issues as well, because the PXI-8252 is only capable of providing approximately 12W of power over its bus. However, I could not find any information on LaCie's site as to what the power requirements of the drive were. Unfortunately I am not fully not clear from your last response - it sounds like you tried to connect the drive to the RT controller via USB, is this right? I think what Steven was suggesting was instead connecting the drive via FireWire, and also connect the USB-Power cable that came with the drive to one of the host's USB ports. I wasn't sure if you had tried this as well. You might also see our article relating to USB on RT controllers if you have not already - KnowledgeBase 40MDORS9: LabVIEW Real-Time and USB Frequently Asked Questions (FAQ).

I also could not find any chipset information about the drive either. As you've probably seen in KnowledgeBase 3HQ8M0DS: Firewire (IEEE-1394) Hard-drive Enclosure Compatibility with Real-Time Controllers, some chipsets do not work with the 8252. However, this document has not been updated in some time to include newer shipsets. Since the drive's specifications clearly state it is SBP-2 compatible, it would seem to me that you should be able to connect it and see it, unless it can still be SBP-2 compatible and yet still have an incompatible chipset. (That seems unlikely to me, however.)

I doubt contacting LaCie and inquiring whether or not their drives are supported in the PharLap OS will get you very far since they probably rarely get questions dealing with real-time operating systems. It may be worth a shot, though. I'll have to see if there're any other resources I can consult here, but right now I'm unfortunately of out of ideas.

[Steve Penney]

Hi Sebastiann/Vijay,

I have previously enquired with Lacie tech support about the power requirements on the portable drives as I needed to get a seperate power supply for one. This was their response:

"We do sell the independent power supplies. It's 5v x 2.5Amp. It doesn't need all that power, though. 5v x 1Amp is all it really takes. We overbuild ours so it can run the 250GB mobile drives (but it would run nice and cool on your 40GB drive.)"

That would mean that their PSU is around 12.5W, but then they say the drive only uses about 5W (not sure if they were referring to my 40GB drive and that the 250GB drives require the full 12.5W). So it may be a power issue and you are on the limits of what the bus can supply. I know that when I plug in my Lacie portable drive into a PC using a long 2m USB cable, the drive LED comes on and I can hear the drive spinning and feel it doing something, but Windows does not see the drive. This is beacuse of the power loss down the long USB cable and it's only when I use the additional power addapter that the drive comes to life in Windows.

Hope this helps,
Steven Peneny