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Data Logger Recommendations 1

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itsmoked

Electrical
Feb 18, 2005
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I have to do capacity tests on a bunch of large batteries (not cells) so I can match them up. This entails reading the battery voltage and current (DC Hall effect coil) periodically and logging them. I'd probably then drag the log into Excel or similar to integrate for the capacity.

I have a really nice Stride instrument that is 8 isolated channels that can only be read via Modbus TCP. I've wasted hours trying to find a simple piece of software that will periodically read a couple of the Stride's registers and log them.

QModMaster seems perfect.. except it's brain-dead. It connects and polls the Stride correctly, the Stride responds with the correct data, then QModMaster decides Error: Address Incorrect freaking out and requiring human intervention to continue.

Advanced TCP/IP Data Logger Is absurd with no obvious way to set the specific register addresses but then the entire product line is like a morass of paid modules working to nickle and dime the victim to their knees.

modbus-tcp-data-logger looks cool and is cheap but completely refuses to even connect. (Likely a PC compatibility nightmare) :/

At this point I'd even go with a portable multi channel logger that (probably comes with) graphing SW side stepping the entire Modbus hassle and doesn't need an external power supply like this Stride does.

My budget is around $200.

SW or Logger suggestions?



Keith Cress
kcress -
 
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I have used the Windmill software on multiple projects for many years,
Based on a quick look at their website they no longer sell the software stand alone, but a lot of their hardware has worked well for me in the past for doing data logging on engine/generator parameters using Modbus and their USB data acquisition units.

Here is one similar to the one I use most, a bit out of your price range.

MikeL.
 
Hey thanks Cat!
Their "750" would do nicely but I'm not thinking this is a good time to try to get products from overseas in a timely manner. :/

That modbustools looks good. Odd they push it as a "tester". Looks more "logger" to me. I'll give it a try.

Keith Cress
kcress -
 
Keith, you're monitoring total battery potential, not cells stacked in series in the battery, right?

Some years ago I found that commercial inexpensive loggers couldn't handle the common mode from one end of the stack to the other and ended up needing a number of isolation 'amplifiers' (really just followers at a gain of 1) in order to make the measurements.
 
Hi Dan.

Yes, cells stacked in series. Eight LiFePO[sub]4[/sub] 24V packs. I have to build them into 48V stacks. I don't want to match a 400Ahr battery in with, say, a 250AHr one causing the 400 to essentially be limited to 250Ahr.

I'll only have one voltage not the common mode of each. I'll simply cobble up a voltage divider to match the logger limit and scale-for-effect after.

Keith Cress
kcress -
 
If you're just going to measure eight points in a battery relative to a common earth, then one of the cheap USB data acquisition units should be fine. I've been using a couple of Mielhaus' Redlab 1008 units for years with very little trouble. I think they were a clone of one of measurement Computing's products - whose current offering in that sort of spec is this: Cheap enough to take a punt on .

A.
 
If you're just going to measure eight points in a battery relative to a common earth

[!]No, no, no, no, no, no, no, no.[/!]

Single readings from 24V battery packs.


Funny zeus; A buddy just dropped that exact logger off for me to use.


CAT: I gave modbustools Modbus Poller a try and it worked flawlessly. Had it logging in about 3 minutes flat. Thanks!

Keith Cress
kcress -
 
Umm, how about RS-232 with a 9-pin Dsub?
I use a 1990 vintage weather station logger to do this in 10-minute intervals. Internal memory can hold a year of data.
There are also a couple of other things monitored simultaneously like temperature inside and outside the enclosure.
I have some spare units in my garage. I would be happy to send you one. Happier to send you two.
Edit: Looks like CAT got you what you need already!

table_kalnwq.png


graph_k7mwl2.png
 
LOL: Thanks again for the offer of a logger Spar!

My current problem is trying to downsize massively. Half my office equipment is currently in my driveway! Your logger would have to reside somewhere like my bedroom nightstand if I had it.

Keith Cress
kcress -
 
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