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  1. Hi there all, this is my first post. I am DIY novice, building a control panel for my 5 axis CNC router. I need help with a few questions. I have 5 power supplies that are 220 volt. Is it an acceptable practice to fuse just one leg of the power input. It seems when using fuses instead of a circuit breaker that trip both legs together, Using a single or double fuse would protect the unit. It seems the problem is if one or two fuses are used, just one fuse would blow and the other leg is left hot, is that a problem? Can I fuse just one leg? Next question. Should I use the same grounding buss bar to ground everything. The main 220 volt power input, the computer, the DC power, the DC control circuit, the machine tool, the stepper motors, VFD, everything? Is there a potential for a ground loop or any other problem? Thanks for your help onthemarc
  2. Hey guys,  Not really new to Allen Bradley per-say but I am very unfamiliar with PID loops and the best way to utilize them.  To be honest I had never even heard of it until a colleague said that it would be the best way to run my program.  Let me know what you think.  Here's the application. I have an Allen Bradley MircoLogix1400 with IF2OF2 analog card.  Controlling the speed of a motor via VFD. 4-20ma signal coming in from the flow meter of water entering the tank. 4-20ma signal coming from scale letting me know how much of the other product is left. 0-10v signal from PLC to VFD to adjust motor speed. The customer is going to have a separate system controlling water into the tank, we are going to use the signal from flow meter to measure how many gallons of water are entering per minute. My system will also be measuring the weight of that product in stock and feed it into the same tank as water at a 10:1 water:product ratio.   The motor will be running an auger that pulls product from stock and dumps it in the tank.  So we will be measuring how much weight is being lost per min and convert that to gallons per minute.  So once i have the rate of water flow in gpm and the rate of flow for product in gpm, i assume thats when the PID comes in?  Can anyone give me some pointers.  I'm positive it's not as difficult as I am making it out to be but again, never used it before so any little bit of info helps!   Thanks

    Okay if I Have a drive with Freqencey signal back and a 4 to 20ma signal to drive the HZ up on the drive and at 300 psi and i need to maintain a Frequency in correlation of the pump curve what is the best way to do that?
  4. Ground Loop

    Hello everyone, I have a quick question regarding Din rails, chassis ground and ground loops. Here is where I am getting confused. I connect my back panel to earth ground which, connects my control panel chassis to earth ground. I screw din rails on my back panel. Question #1: logically, my din rails are now connected to earth ground through the screws connecting to din rails to the back panel. Am I wrong here? As I have seen in many control panels, I connect a ground terminal block to my din rail and connect it to earth ground (the terminal block couples with the din rail through metal clamps). I now use that ground terminal block as a single point source to ground all my other components in the control panel (I connect my ground terminal block to earth ground using a wire).. *** the ten thousand dollar question is Didnt I just create a ground loop between my ground terminal block mounted on the din rail and my back panel chassis ground. For one reason or another the two different location might be at slightly different potentials causing current to flow. Where is my logic off here???? Thank you
  5. Logo!8 sensor compatibility/display

    Hi there,  I am brand new to the world of PLCs. I'm working on a project and we will be using the LOGO! 8. We will be monitoring a tractor's ground speed, wheel speed, (wheel slip using those two), oil pressure, tachometer, EGT, and system voltage.  As I said, I'm brand new to all of these things. Any tips or advice to get started? Or things to avoid? Specifically when choosing sensors. Also, we were thinking of a tablet to display these measurements in real time. Any suggestions? I was thinking the Simatic HMI touchscreen may be a better option for compatibility. This will be on a competition tractor, though. From experience, how durable/rugged are these displays? It would mostly be subjected to dirt, vibrations, and quick jerks.  Any advice to help guide my Googling adventures would be greatly appreciated!  Thank you.
  6. Version 1.0.0


    Temperature measurement usind Arduino Nano, RTD PT100 sensor,  4-20 mA current loop transmiter, and a python app for visualization
  7. View File Temperature measurement using Arduino Nano, RTD PT100 temperature sensor and 4-20 mA transmitter Temperature measurement usind Arduino Nano, RTD PT100 sensor,  4-20 mA current loop transmiter, and a python app for visualization Submitter Absolutelyautomation Submitted 04/01/16 Category Other PLC Demo Software
  8. Is it possible to run some sort of PID operation on OMRON PLC without PID or PIDAT instruction? I need to modify a program and although it seems that they use PID loop to control temperature I can not find PID or PIDAT instruction anywhere in the whole program. Can they put the instruction somewhere where the find function would not see it? Also what is this instruction --|| |--? I looked through the instruction manual but did not see one like that in there so what is it?