Control.com - Nerds in Control

Hello,

I'm currently in the process of building a data handler(DH) for an oceanographic application. In the DH, the data streams from several instruments(RS-232,RS-485, and analog voltages) are converted to an ethernet data stream. The DH consists of a pressure case (which limits space), a serial server, an Advantech ADAM-6017 Ethernet IO device, and an ethernet switch.

Well, the requirements recently changed and the 10Hz sample rate of the ADAM-6017 is no longer sufficient. We need at least 200Hz. One difficulty is that I need a device approximately the same size as the ADAM-6017 (~4.75"x3"x1.25") or it simply won't fit. I've looked at LabJack, Dataq, B&B Electronics and others and I haven't found anything quite like what I need. Frankly, there's quite a lot to sift through and I though some advice from those with more experience would be useful. 200Hz isn't really that fast. I would think it would be fairly straightforward, but my size limitation has not helped.

I might be able to fit a VERY small device in addition to the ADAM-6017.

Thanks in advance for any help.
Eli Hunter
Marine Scientist
Rutgers University

I checked the datasheet on the Advantech-6017 module and it indicates an update time of 10 samples/sec for all channels.

If you're looking for similar product(s) with faster update rates, try checking out the Acromag Model 967EN-4C08 (8ch Diff AI-I) or Model 968EN-4C08 (8ch Diff AI-V) modules. These devices update all channels in 8mS. It's not quite 200hz for all channels but it's much closer.

Acromag also has products with much faster scan rates as well although the form-factor is a little bigger (ie; see the EtherStax Models ES2161, ES2162 or ES2153).

Link to the 967EN Datasheet:
http://www.acromag.com/parts.cfm?Model_ID=386&Product_Function _ID=53&Cat
egory_ID=22&Group_ID=2

Link to the 968EN Datasheet:
http://www.acromag.com/parts.cfm?Model_ID=387&Produc t_Function_ID=53&Cat
egory_ID=22&Group_ID=2

If you have any questions or I can assist, please let me know.

Kind Regards,

Donald Lupo (dlupo@acromag.com)

I've never bought anything from the following, so I can't exactly recommend them. However, you might want to have a look at them. They have the most interesting hardware that I've seen because they have very large on board buffers instead of relying on streaming. I don't have dimensions for it, so I don't know if it will fit. When you follow the URL, watch out for the spaces which the forum software inserts in the path.

http://www.eagledaq.com/display_cat.php?subcategory_id=11 04

The following link is to National Instruments. I haven't used this device either. Their hardware used to be top of the line, but I'm not sure if I would trust their newer stuff. In depth documentation on this hardware seems to be almost non-existent so you'll have to contact them to find out how it really works inside.

http://zone.ni.com/devzone/cda/tut/p/id/7374


Advant ech seems to sell the fastest "industrial" hardware. Their fastest systems go up to 100 S/sec for the 5000 series. Those are in a (small) rack though, so that might not fit in your package. They have versions that go up to 1k S/sec., but that requires an attached controller, rather than a simple network connection.

To go faster than that, you have to go to "data acquisition" hardware, which starts at 50k S/sec/, and a big jump up in price.

There is a lot of new types of data acquisition hardware on the market these days, but 99% of it is just junk. I wouldn't touch most if not all of the USB stuff as most of it is very poorly made with very poor specs.

If you can do C programming, look at the single board computers from Rabbit Semiconductor. They are small and powerful.

Bill Sturm