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mos89

high speed counter + analog output

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Dear all I want to control a servo drive via analog +/-10V, and get the position from encoder . I am using 1769-HSC+1769-IF4XOF2 +1769L32E processor . How to set +/-10V with the 0-10V analog output ? I have difficulties to set up the HSC, i just want a simple mode to be able to count to compute the linear position. thanks in advance !

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Do you already have the hardware? Have you thought about the SERCOS for the Compactlogix or bumping up to the Controllogix with a M02AE? They are more suited for your requirements

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i can count, but how to reset the counter ?

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Say your HSC is in slot 1 MOV a value of "0" to Local:1:O.Range12To15[0].HiLimOrDirWr Unlatch Local:1:O.Ctr0En Turn on Local:1:O.Range12To15[0].LoadDirectWrite Latch Local:1:O.Ctr0En What you are basically doing is disabling the counter, then using the LoadDirectWrite bit to write the HiLimOrDirWr to the counters accumulated value, then re enabling the counter. The counter value cannot be changed while the counter is enabled It should look something like this

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i try your tip, but it is not working

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What you have should work. What happens when you toggle the reset_HSC bit? Screen capture with the bit off.

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Here is the screen capture my encoder is not rotating during the reset

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I reset all default value, and the reset is ok now thanks for your help do you know well Analog output ?

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Going to have to know a lot more about your application for that. Servo control with the HSC is hard, that's why I asked about your hardware. Your analog output will be dependent on what the true requirements are of the application.

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in fact i have to control a parvex drive via DLD servo, my servo input is +/-10V, and i am using the HSC to compute length. I did it previously with omron material, but the analog card was +/-10V. My AB material is 0/10V i am looking how to be able to rotate both side with it ?

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What exactly is the machine doing? How accurate does it have to be? Can it creep into position or does it have to stop immediately at the correct position? Must it act as a true servo system or a crude positioning system?

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Sorry but that doesn't help me. What is a dosing machine?

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the aim of the machine is to control the quantity of product with the motor encoder

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A dosing device is one that delivers a measured quantity of material, aka "dose". The "dose" needs to be accurate and repeatable. There a many ways to accomplish this, with out more details from the OP, it's hard to guess what type of hardware is being used. The physical properties of the material to be "dosed" are also a factor. Wet, dry, liquid, powder, viscosity, etc..... Quantiy to be dosed and tolerance are also factors. EDIT: Looks like he's using a cavity of known volume to "measure" the dose. I would guess that the the cylinder moves down, displacing material out of the cavity, the encoder gives you positional feedback, and the servo controls the movement of the cylinder (the photo says electric motor is an option). You would have to know exactly how much travel is needed for a dose. I used to do a lot of adhesive dispensing and this type of arrangement was common, in many cases, after the cylinder travels down to the desired location, it stops, then retracts just a little. The retraction "sucks" the material back up the nozzle just a tad, this is done to minimize dripping. It is often used in marketing, the sales guys harp about the "suck back" drip prevention feature. So.... if his servo is looking for -10 / + 10, the best solution may be to purchase a signal converter, that has 0-10 as an input and -10/+10 as an output. I've never used the Compact Logix's platform, don't know if there is a -10/10 output card available or not.

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good explanation, i do not have the correct vocabulary to describe well the process ! for my case it is only electrical motor, wa have done this application on siemens, and Omron

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1769-IF4XOF2 will do +/- 10 VDC out. Check the property tab on the module channel of interest. There should be a drop down selection for output configuration.

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in the documentation theu sais 0 to 10v

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The IF4XOF2 doesn't have the output configuration feature. Best solution may be to install a 1769-OF2, they do support -10/+10

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I guess the selection guide that I referenced has an error. Mia copa.......

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answer today from tech support: no +/-10V with this device. I need to buy a new one...

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