Great Lakes Cal

I had a similar project and found a great solution. I used a high speed DA system for load cells from TEAC. Model TD-SC1. It has a DA rate of 20-khz. It also has a 0-10 volt output also at 20-khz. I connected my load cell to the TD-SC1 and the output of the TD-SC! to an MCC USB-230. Then used DASYlab to monitor the USB-230 and do what i needed to do with the signal. i was able to set up scaling modules to calibrate the 0-10 volt output from the TD-SC1 so that i got proper load readings from USB-230. It worked really well.

Would i be able to use a TC-32 and 11 expansion modules with Dasylab to display 360 thermocouple inputs and log data to 180 different files (2 channels per file). i wouldn't need all 360 digital meters on one view. we can create several views to be bale to see all the inputs. Or would it be better to split it up and use a couple TC-32's with expansion modules and run Dasylab on a couple different computers and split this up?

I'm still trying to find a solution for a highspeed data acquisition unit for a low voltage signal of a load cell. I found a device from a manufacturer that we use for standard load cell meters. they have a fast module with a 4,800 sample per second DA rate. would it be possible to use this with DasyLab? their software is too basic for what i need. Here is a link to the module. https://www.mantracourt.com/products/signal-converters/fast-usb-strain-module#downloads

i only need one channel for one load cell input to measure the voltage from the load cell. i need to sample at at least 2,500 hertz.

still doesnt seem like the USB1616 is a good choice for low voltage measurements. not sure why it was recommended to me. i guess just because it has the sample ate i needed and a 100-mv range. i think al of the other modules with a higher sample rate dont have less than a 1 volt measuring range. if the USB-1616 has an input noise spec of 427-micro volts, it's going to be very difficult to measure 200-microvolts or get a stable reading at 0-lb which would be 0-volts. are there any other options? not sure what to do with the USB-2416 and the USB-1616 i bought now. these two as well as the USB-2408-4AO were what was recommended i buy based on my 20-mv measuring range and at least 2,500 hertz sample rate.

the load cell output is +/- 20 mv with a 10-volt excitation. 0-mv at 0-pounds and 20-mv at 10,000-lb. most of the testing they do is between 100 and 5,000-lb. so we would be measuring 0.2-mv to 10-mv. i had to make the switch to the USB-1616 because i needed the faster sample rate. the 1-khz sample rate of the USB-2416 was not enough. i'm starting the get the idea the there are no good options for both low voltage and fast sample rates

I have a USB-1616HS-4 that i just got to replace a USB-2416. i switched modules to get the faster DA rate. i have the 1616 set to 10-khz. I have the signal wires of a load cell connected to the CH0 and CH8 terminals. i also tried connecting the ground from the 10-volt excitation voltage supplied by an external source to the S (signal ground) terminal but didnt see any difference. When i have Instacal open and start the analog test i can see a stable voltage from the load cell that changes when load is applied to the load cell. the voltage displayed would be what i would expect and it all looks good. but when i attach a digital meter to the analog input module in DL, i just see a bunch of jumpy numbers that dont look at all like what i see in Instacal. how do i get a nice stable voltage reading from my load cell in DL that matches what Instacal shows me? i have tried averaging modules and digital filters. the averaging modules just make the numbers jump around slower. the filter modules, one high pass and one low pass result in a 60-hx sine wave. what would be the best approach for connecting the load cell wires to the USB-1616 and what would be the best method in DL to get a solid cleans display of the load cell voltage? thank you

Thanks for the info. I am only using 1 sensor. it's not exactly a load cell. it is a trensile sample, dog bone shape, with 4 quarter bridge strain gauges bonded to it and wired in a wheatstone bridge configuration. it works just like a load cell though. the out put ia am seeing is 20-mv at full scale. that's using the 5-volt output from the 2416. i do need a much faster DA rate to capture peaks and valleys of sine waves of the load input where the load is cycling at 40 hertz. so i will need to look at exchanging this 2416 for somthing faster that has a low voltage measuring range. any thoughts? but for now, i need to figure out how to hold a peak and valley in a digital meter and have the meters only update if the load goes higher or lower than the currently displayed max and min. the meters i have in teh worksheet now are updating on ther own and i think they update every data block. i added averging modules to slow the update rate down. but i would rather they just hold a max and min until i reset with a button and action module. update... i figured out how to get the maximum value to hold and reset. but i cant get the minimum display to show anything other than 0. Astro DA Program.DSB

i have the load cell reading now and replaced the analog input module so i dont get the differential or single ended error. but now it wont let me go any higher than a 57 hertz scan rate. how do i get this to 1-khz which i think is the fastest it can go. it tells me to decrease the nukmber of channels or decrease the scan rate to 57. 1000 hertz is too slow for what i need and 57 is just not ueable at all. what's the trick to get it to 1000 hertz? My next issue is a peak and valley hold display. i have digital meters set to maximum and minimum. how do i get it to display the max and min and hold those values there until i reset the meter with a reset button. it looks to be resetting on iots own every data block. how can you make hold a peak and valley and display and lower or higher numbers that may come in but keep those max and mins until manually reset with an action module and button?

I got my USB-2416-4AO module yesterday and i connected it to my computer and changed out a generator module for the 2416. i connected a load cell to the CH0 inputs. i can measure 0 volts with no load on the load cell and 20-mv with 10,000-lb. if i go into the analog input module i can see the current channel value. sometimes its correct but most of the time its just bouncing around -0.017 volts and not showing the correct input voltage. i also have a digital meter connected directly to the analog input module. i have this meter set up in layout-2. i see the same thing here. sometimes it's correct but mostly shows -0.017 volts. it also looks like this 2416 has a max sample rate of 1-khz. this is not enough i need at least 2500-hz. I'm not sure why this module was recommended based on my requirements but it think it's not going to work for me. but for now it is telling me that it can only be set as high as 57 hertz for the data rate. how do you get it to it's maximum data acquisition rate? one other thing DL keeps telling me every time i open the worksheet. it gives me a message box that says the last time the woskheet was saved the input was set to single ended but it is now set to differential. and to run instacal to set the input to single ended. i only have one input but i would think differential would be the more appropriate selection. Astro DA Program.DSB

If i use and offset adjutsment module to zero or tare the load cell live display, is there a way to remove the offset adjustment so it's back to displaying the input with no adjustment?

Thank you. that is perfect. There may be a time when the cycle between something like 500-lb and 0-lb. but then all the math would be a problem becuase a 2% tolerance of 0 cant be calculated. but i dont think that will ever come up. so this is a great solution. thank you

Thanks John. the One Windows action module took care of the graph. now i have one last issue to resolve. we are graphing a sine wave. some times the peak and valley will both be greater than zero. sometimes the peak is greater than zero bu the valley is less than zero. in my worksheet i have two graphs to show a close up view of the peaks and valleys and the 2% tolerance that they need to stay within. i am using global variables to set the Y axis scaling to values a little higher and a little lower than the 2% tolerance of the peak and valley. the math functions i am using in the global variables works just fine when the valley is greater than zer. but when the valley is less than zero, the y-axis scaling does not work out becuse the begining value ends up being greater than the end value and the graph does not scale properly. for example, if we set the amplitude to 1,000 and the set point to 0, the peak would be +1000 and the valley would be -1000. global variable 15 is used to set the begin value for the y-axis scale and global variable 14 is used to set the end value. GV 15 calculates to -979 and GV 14 calculates to -1030. so the begining value is greater than the end value and the graph sets the scale -979 for the low and high both to -979 and you see no graph. the question then becomes, how can i get global variables 14 and 15 to switch when the valley is less than zero? Astro DA Program.DSB

I have a sine wave that i would like to graph. but i would also like to graph a line that is 2% above and below the nominal peak and valley. for example, if the nominal peak is 1000 and nominal valley is 100, i would like to graph a line at 1020 and 980 and then at 98 and 102. these lines would provide a visual guide to the 2% tolerance the the peak and valley of the sine wave needs to stay within. the sine wave will be coming from a load cell. the worksheet i am working with now uses a generator to simulate the load cell. i am using another genertaor and global variables to output the plus and minus 2% values. my first try was with a chart recorder but it puts each input on its own axis and not on the same axis. my next try was a yt chart but that is giving me an error. how can i graph a sine wave from one onput plus the four addisonal lines to mar the 2% tolerance of the nominal peak and valley all on one graph? Astro DA Program.DSB

Thanks John. that is genius. i would have never thought of that. i also added a write module to writ the data to a file. is there a way to make that list display scrollable when you put it in a layout? i used the Link Graph option in my layout and tagged the list to it. but when the list gets longer than the window, you cant see any more listed data. also in the layout view, i cant find a way to copy the list to the clipboard. i see that option in the worksheet view when the list window is expanded. but not in the layout view. thanks for the help TUS Data Logger.DSB