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Showing results for tags 'loadcell'.
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Hello friends, I am new to Unitronics hardware and have about 1 year experience with ladder logic (studio 5000 up to this point). I am tasked with writing a program for a machine that uses the following components and I just need some help on choosing the right Unitronics PLC and what snap-in's I will need to work with the components: -conveyer belts (1 requires indexing/location tracking) -motor driving an actuator -motor moving a tray back and forth along rails -9 load cells I am leaning towards the Vision 350 TR20 currently, and it looks like the IO-LC3 module supports up to 3 load cells each, so I will need a PLC that supports at least 3 expansion ports (one for each IO-LC3) Also, in general I am wondering about how servos/motors are added to a program using Unitronics, it seems like there us usually a data bit to enable the servo (maybe controlling the power supply) and then a bit representing motor go/stop? Any help you all have is greatly appreciated, thank you in advance! -
Machine has 4 load cells (30klb each, 2mV/V) into a Summing Box, then the single output from the summing box going into LC2 on an I/O LC3. The Load Cells are measuring clamping force of a bolted joint and, as such, there is no real way to put a reasonable known weight onto the LC's and hit "Calibrate." Eventually we'll have a calibrator come out with a through-hole Load Cell to dial it in, but we need to get it in the ballpark to get started. In this application, relative values are more critical than accuracy so if we're off 5% no big deal. I used some simple math to determine that it should take 111,000 or so pounds to reach 80mV/V output which is the top of the scale. Question is, if I use Edit Calibration Point and fake in a Zero and a Full-Scale Output point, will that get me reasonably close to accurate? I thought it seemed workable - theoretically 0.8mV (80mV/V * 10V Excitation) should end up at a Raw value of 8,388,607. But, when I was looking at data the Raw values were about 1/8th of the pounds I was expecting to see, so that kind of shot my theory up a bit. Anyway, hopefully this makes some sense and someone can shed some light!