Products > Test Equipment

Agilent HP 54831D advice

<< < (3/8) > >>

Wuerstchenhund:

--- Quote from: Howardlong on October 05, 2014, 08:59:40 pm ---My understanding is that OSes such as XP not supporting TRIM can use a scheduled housekeeping task run on occasion. My main concern was boot time, although I agree it's not necessarily all about the disk.
--- End quote ---

You can, if you find a trim utility which actually works (I never found one which did). Some industrial SSDs have proper garbage collection procedures which offset the lack of trim support in older OSes, but these SSDs tend to be quite expensive. Garbage collection in normal SSDs is usually pretty poor as they assume trim support by the OS.

In addition, many SSDs seem to have issues with slower UDMA modes (UDMA/33) and PIO modes on certain controllers, which then usually results in silent data corruption.

For old hardware like a 54800 Series scope I'd recommend to go with a PATA-SATA bridge adapter and a modern 2.5" laptop drive instead. These drives are dirt cheap, reasonable rugged, noticably faster than the original PATA drives that came with these scopes, and they avoid all the issues re. trim and UDMA/PIO modes and won't get slower over time.

However, if for some reason you really want go ahead with XP on a SSD then make at least sure that certain things like background defragmentation are disabled, as this shortens the life of the drive.

Wuerstchenhund:

--- Quote from: edavid on October 07, 2014, 04:31:33 pm ---Do you know of a PATA-SATA bridge that works reliably?

--- End quote ---

Good ones are usually those with SiL or Marvel chipset. They can be found on ebay for a few bucks. I've used lots of them for upgrading older T&M and embedded kit with modern SATA drives, no issues so far.


--- Quote ---XP doesn't have background defragmentation  :-// 

--- End quote ---

Ahem...

http://msdn.microsoft.com/en-us/library/ms932871%28v=winembedded.5%29.aspx

http://ckirbach.wordpress.com/2012/11/13/how-to-optimise-windows-xp-for-ssd-solid-state-disk-operation/

It's not a full background defrag as in Vista and later, though.


--- Quote ---You can turn off the page file if you don't need it.

--- End quote ---

Turning off the page file isn't a good idea unless you use something like a CF or SD card which has a very limited amount of write cycles (and even there it's just a crutch). If the system is paging a lot then this is a sure sign of too little RAM, in which case using a SSD as system drive is somewhat non-sensical.

Howardlong:
Just to tail this one off, I received my 54831D scope this morning, very nice it is too. I can't seem to get the secondary display to do anything more than reflect 1:1 the LCD, but my secondary display has a USB touch screen on it which works surprisingly well with the scope software. The video card only has 1MB RAM, so that's your 640x480x24bpp completely taken up.

It's taken all day to do backups and update the OS and firmware/software to the latest versions. Most of this was XP updates, probably a couple of hundred of those in total, with the .NET updates taking forever. What a crock!

The SSD is installed, as is a USB 2.0 card. Now I just need to learn how to drive it.

Thank you everyone for your help.

Howardlong:
I have some further updates now I've been using this scope for a couple of days.

Compared to my old Tektronix 2Gsps/200MHz/4ch TDS 2024B 5.7" screen (which has a resolution of 320x240), the 4Gsps/600MHz/4+16ch 54831D 640x480 in 8" is clearly going to be an improvement. I have also added an external monitor which can also act as a touch screen duplicating the main display. It can also be hooked up to extend the desktop to the motherboard display at up to 1280x1024. Because the external 10" monitor is 16:9, and the native VGA ports only support 4:3 resolutions, I've used a DisplayLink USB adapter which supports 1280x720 and sits above the main screen. Surprisingly the DisplayLink adapter takes very little CPU, usually about 1% unles there's a big screen update.

As discussed previously in this thread, the scope app will only run on internal LCD and an external monitor duplicating the 640x480 LCD. It is locked to that graphics card and will not display on the motherboard's VGA port.

So what's the benefit of an external monitor? Well, you can put all the scope app's modeless dialog boxes that would otherwise clutter up your 640x480 main scope screen, and have anything else you choose up there, like the scope help documentation, or a web browser or MS Office for example which won't work very well in 640x480 anyway. Don't expect too much web browsing or videos to work well, Youtube manages about 2 fps on the main screen.

There are three SDRAM slots in there with only two populated up to 512MB. I tried a third today but it wasn't recognised, I think this is a chipset limitation, although it may be BIOS related. I have no intention of updating the BIOS, that sounds like a recipe for disaster.

I'm successfully using a USB keyboard and mouse plugged into one of the two motherboard USB 1.1 ports and the keyboard is recognised by the BIOS.

Using Acronis True Image to make disk images work both over the LAN and through the USB 2.0 card I added, although you have to override the default video probing in my version. To restore an image, I couldn't make it work over the LAN, I had to use a USB 2.0 port.

As a scope, it's a bit of a beast. Yesterday I was debugging some TI CC3100 WiFi firmware from an NXP ARM Cortex M4 device, and was probing the SPI bus running at 20MHz. Pretty soon I dropped into just using the logic analyser rather than the analog channels as it's easier to plug in the pod than mess with scope probes all the time. The scope is configured with the low speed serial data analyser and 64Mpts options, although the LA uses its own 32M samples per port memory. Now I may be wrong but the low speed serial option might be called low speed because it does take an awfully long time to update from either LA or analog channels. It's simple and quick to set up, but if you have a full buffer, real time updates are pretty much unusable. Using segmented acquisition judiciously helps here by reducing the amount of samples to interpret. There may be another way of setting it up of course, and I welcome any inout here. Having the serial data dialog box handy on the secondary monitor to disable and enable the decode helps a lot here. I noticed there's no RS232 decode, but maybe you can custom configure that.

Is the 54831D LA better than my Logicport? Well, the Logicport has 34 channels compared to the Agilent's 16, although I've only ever come close to using more than a dozen which was when I was debugging a parallel interface on an LCD display. The problem with the Logicport is that it runs out of memory very quickly, but it does do true real time serial decode and on a PC screen with a couple of 4k monitors you get to see an awful lot in one go. Where the 54831D wins is on its relatively massive 32M samples per channel on the LA whereas the Logicport only has a meagre 2048, although I should stress that it uses some fairly mean compression so it feels a lot more than 2048. However the biggest drawback of the Logicport is that it doesn't take much to find its buffer is just too small. Add to that the Agilent's segmented acquisition feature and it makes the Logicport seem a little quaint. However I have no intention of giving up the Logicport, it's served me very well for nearly ten years, and I expect it to continue to do so in certain situations.

Today I've been working on a high speed sample and hold (30Msps) using the scope's four analog channels and for that it's been awesome. My design suffers from some opamp instability that's taken me most of the afternoon to investigate, and this scope is just so much better for this than my old Tek. For reference, I measured the 3dB bandwidth with an RF signal generator on a 50 ohm channel and although it's quoted at 600MHz I was up to 820MHz before it hit the 3dB point. I was on a single channel, sampling at 4Gsps. It's the first time I've had a scope where you can see things sub nanosecond.

More generally although some folk aren't over keen on Windows on a scope, what's nice with a Windows based scope is being able to do mundane things like print a screenshot to your existing printers directly, or copy stuff to storage on your LAN without having to mess about with USB sticks.

On the downside, this scope has no fewer than six fans, so it's a noisy bugger. While it doesn't bother me too much, I am aware that some folks like their peace an quiet. Also, compared to the Tek, it's heavy and large. Both take a while to boot.

Now this second-hand ten year old 54831D cost just about the same as my brand new TDS2024B did maybe eight years or so ago. I realise the market's changed more recently with the likes of Rigol now being a serious contender at the TDS end of the market. However I would seriously recommend considering the second hand market before diving into a brand new scope.

Wuerstchenhund:

--- Quote from: Howardlong on October 12, 2014, 12:02:40 am ---More generally although some folk aren't over keen on Windows on a scope, what's nice with a Windows based scope is being able to do mundane things like print a screenshot to your existing printers directly, or copy stuff to storage on your LAN without having to mess about with USB sticks.
--- End quote ---

I actually prefer a Windows scope over an embedded one, mainly because it allows me to run other programs (i.e. Mathlab and other analysis tools) on the scope. Then there's the mentioned ease of data transfer, i.e. via USB drives (no size limition, exFAT and NTFS support, not limited to USB flash drives), the better print support, the much better multi-monitor support (at least on the LeCroy Windows scopes as they don't have the scope app limitation of the Agilent 54800 Series) etc.

The boot time is certainly a disadvantage but for a desktop scope that shouldn't matter that much (at least it doesn't for me). It's probably a different story for a portable scope, though.


--- Quote ---On the downside, this scope has no fewer than six fans, so it's a noisy bugger.
--- End quote ---

That's true but scopes with very fast ADCs are rarely silent as their hybrids generally output a lot of power as heat.


--- Quote ---Now this second-hand ten year old 54831D cost just about the same as my brand new TDS2024B did maybe eight years or so ago. I realise the market's changed more recently with the likes of Rigol now being a serious contender at the TDS end of the market. However I would seriously recommend considering the second hand market before diving into a brand new scope.

--- End quote ---

I second that! There are many good deals out there if you're looking for an advanced scope and have some patience.

Navigation

[0] Message Index

[#] Next page

[*] Previous page

There was an error while thanking
Thanking...
Go to full version
Powered by SMFPacks Advanced Attachments Uploader Mod