Data Logger: what would you recommend? - Page 1
Forum section: electronics / testgear

author: enut11
author_rank: Super Contributor
timestamp: May 17, 2016, 09:28:15 am
content: Hi AllI want to experiment with data logging and analysis. Would like some recommendations on suitable hardware/software.I appreciate that it depends on what sort of data I want to record and analyse.To begin with, it will be low level voltages. I want to measure the noise level of various pieces of test equipment.Also need USB connection to PC. Lots of equipment have RS232 or GPIB outputs which I cannot use.enut11

author: ADT123
author_rank: Regular Contributor
timestamp: May 17, 2016, 11:23:28 am
content: If you want to measure noise, you need to think about the bandwidth / spectrum of that noise. Many data loggers are fairly slow so could even struggle with 50 / 60Hz noise. If noise is from switched mode power supplies you may need to record data at several million samples per second.Sort this part of the question out first, next think about how long you need to record this for and then think about channels / resolution / cost etc.

author: joeqsmith
author_rank: Super Contributor
timestamp: May 17, 2016, 11:35:23 am
content: Agree.

author: enut11
author_rank: Super Contributor
timestamp: May 17, 2016, 09:05:04 pm
content: Looking to buy this unit. Anyone with experience on Octvolt data loggers?Model OM-CP-OCTVOLT-2.5V Data LoggerNominal Input Range 0 to 2.5 VMeasurement Range -0.25 to 2.75 VResolution 0.1 mVAccuracy ±0.01% FSRInput Impedance >1 Kohm (>1 Mohm during acquisition)Overload Protection ±5 VSpecificationsInput Channels: 8Memory: 16,383 readings/channelADC Resolution: 16-bitsRecording Interval: 1 secondto 12 hours selectable in softwareReal-Time Recording: Device canbe used with PC to monitor andrecord data in real-timeTime Accuracy:±1 minute per month at 20°CData Format: Date and timestamped; µV, mV, V and otherengineering units programmablethrough softwareComputer Interface:PC serial, RS232C COM or USB(interface cable required);2400 baud

author: enut11
author_rank: Super Contributor
timestamp: May 17, 2016, 09:14:45 pm
content: Quote from: ADT123 on May 17, 2016, 11:23:28 amThanks ADT123. At this stage I do not really know so it is difficult to make an informed choice. Looks like lots of homework for me.As this is hobby I do not want to spend a lot of money. I want to start out with a cheap logger and see what it is capable of.Getting data into a PC seems a problem for me. I have tried 3 different RS232 to USB adapters with no success. Am using Win 10 PC.

author: nctnico
author_rank: Super Contributor
timestamp: May 17, 2016, 09:21:42 pm
content: You may want to change your software. It seems a lot has changed in the way serial ports are handled in Windows 10 so some software may no longer work.

author: ADT123
author_rank: Regular Contributor
timestamp: May 18, 2016, 04:27:45 am
content: Any unit like that octvolt one that still uses RS232 is probably a decade old design and to be avoided. Sampling at 1Hz is no use for your noise measurements and the built in memory of 16K per channel is a bit of a joke these days.Look for something with a USB or wireless connection. Try dataq, national instruments, pico technology etc

author: enut11
author_rank: Super Contributor
timestamp: June 21, 2016, 06:45:54 am
content: Well, I have given up trying to use Win 10 for data logging and have gone back to a Win XP PC with RS232 port.The first project was logging from my Mastech MS8040. This unit has a resolution of 0.1mV on the DC range and I was able to log mV signals using the supplied software.Now looking at using my Yokogawa 7552 bench DMM as it has an order of magnitude better performance compared to the MS8040. The 7552 has a 25 pin RS232C port and the pin assignments are available in the manual.Looking for suggestions on PC software to log from the 7552 RS232 to XP RS232, both commercial and free. Data analysis can either be within the software or external using XL.enut11

author: Wuerstchenhund
author_rank: Super Contributor
timestamp: June 21, 2016, 11:13:03 am
content: Quote from: ADT123 on May 18, 2016, 04:27:45 amFully agree. Devices like that are too limited and essentially money flushed down the drain.QuoteAt work we use National Instruments USB-6225 and 6255 acquisition systems which have proven to be really robust and reliable.They're not cheap but you you get what you pay for. And NI has some really great support.

author: joeqsmith
author_rank: Super Contributor
timestamp: June 21, 2016, 05:47:58 pm
content: Quote from: Wuerstchenhund on June 21, 2016, 11:13:03 amI wish I could say the same for NI support. I do like Labview for the most part and I still use their Ethernet GPIB interfaces but that's it.

author: PedroDaGr8
author_rank: Super Contributor
timestamp: June 21, 2016, 07:43:59 pm
content: I used theNational Instruments NI-9205with thecorresponding USB module. The total price comes to around the same as the list price for the DAQ you mentioned. They have worked beautifully, in the system I designed. I'm a chemist, not an engineer, though I still got tasked with creating a digital "chart recorder" system to monitor our chromatographic columns. Though I still want to shoot the idiots who designed theBioRad UV-detector, lets put up to 800mV of noise on a signal that has a maximum 0-1000mV swing, usually much less. Luckily, a quick pi filter took care of that real quick. Was able to get around +/- 1 bit or so of noise on the DAQ after filtering which worked perfectly.LabVIEW, with the training included in our purchase, was easy enough for a programming idiot like myself to bang out a fully functioning program.

author: enut11
author_rank: Super Contributor
timestamp: June 22, 2016, 01:33:17 am
content: Thanks everyone. Before I get into the professional software, is there a free data logging program out there that works with RS232 so that I can get to know what my Yokogawa 7552 can do? Looking mainly to log voltage and resistance data.enut11

author: joeqsmith
author_rank: Super Contributor
timestamp: June 22, 2016, 04:23:16 am
content: Yes, Labview. Get your sparkfun kit with the water marked version for $50 and toss the hardware away. Or, maybe use the hardware for you acquisition system. This is basically a watermarked version of the base package. It does not appear to be crippled in any way.If you really want free, Python or pretty much anything can handle the serial ports.

author: Wolfgang
author_rank: Super Contributor
timestamp: August 11, 2018, 12:47:28 pm
content: Hi,I use a RIGOL M300 to measure some voltages, current via a shunt resistor and temperatures.So far, it works OK.electronicprojectsforfun.wordpress.com/silly-circuits/silly-circuits-a-heated-lm723-reference/