Raul Posted August 5, 2011 Report Share Posted August 5, 2011 I am very new to PLCs, but I have learned a lot during the past few weeks and I finally managed to program the routine I need except for the loadcells. I have read and re-read every single help topic and example available regarding loadcells. I have also consulted the new and old forums but I'm still stucked with this issue. I can place the loadcell calibration FB along with the scan, tare, zero and write to eeprom commands. I do get readings but unfortunately I'm afraid those readings are not being converted to actual grams. For some reason the read zero is not working for me. Also I have no idea on how to linearize the variable I'm using on the HMI. I know the Y range is 0-1000 grams but I have no clue regarding what should be set on the X range. The loadcells are 2.2 lbs made by FUTEK model LRF400. they have an RO of 2mV/V nom. and a zero balance of + - 3% of the RO. I'm not sure if I need to set the gain and offset for the LC, the reading between +SG and -SG is 0.1mV AC. I would really appreciate your help in order to finish this project. Quote Link to comment Share on other sites More sharing options...
MVP 2023 Joe Tauser Posted August 6, 2011 MVP 2023 Report Share Posted August 6, 2011 What is the model number of the PLC you are using? Joe T. Quote Link to comment Share on other sites More sharing options...
Raul Posted August 8, 2011 Author Report Share Posted August 8, 2011 It is a Vision 130 33 RA 22, the loadcell module is the IO-LC1 Quote Link to comment Share on other sites More sharing options...
Stein Yair Posted August 8, 2011 Report Share Posted August 8, 2011 Hi, You do not need to enter the X range yourself. The X range value comes from the LC. In order to calibrate the LC please do the following: Prepare an object whose weight you know for sure. Store that weight in an ML, put that object on the LC and activate the Calibrate Point function with that ML. Do the same with no weight and another ML which holds 0. Quote Link to comment Share on other sites More sharing options...
Raul Posted August 8, 2011 Author Report Share Posted August 8, 2011 Ok so this was much more simple than I thought. Thank you very much. I have one more question for you. How do I get the PLC to capture a weight value and store it on a table every cycle so that it can generate a report were I can read the weight change that occurred on each cycle? Exporting it to excel would be great but I just need to be able to print out a report on whatever format. Thanks Quote Link to comment Share on other sites More sharing options...
Raul Posted August 8, 2011 Author Report Share Posted August 8, 2011 Hello, The loadcell works great, but I need to keep it from oscillating so much when it comes to the smaller readings. I set the scale to 000.0000 and rounded the last cero to 10. Is there something else I can do so that I can get a stable reading to 000.000? I'm measuring water drops so its a bit critical to be able to have a stable reading at this resolution. Quote Link to comment Share on other sites More sharing options...
MVP 2023 Joe Tauser Posted August 10, 2011 MVP 2023 Report Share Posted August 10, 2011 I've found that AC excitation on the LC1 is more stable than DC. Joe T. Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.