We are currently using a USB-18080X board trying to read a linear encoder by means of the ENC0 input channel. We are experiencing a strange behaviour: when this encoder is moved statically by hand (for example 20 mm displacement), we are able to measure this displacement with the ENC0 signal correctly but when we put the linear encoder in our system in which it moves step-by-step measuring an intermittent incoming fuel volume, it seems we are able to follow the dynamics of the system but the overall measured displacement is lower than the real. We measure the real displacement with another board which has been widely validated and the consequent fuel volume measurement has been also validated independently. The particular behaviour is that, if we plot the real measurement and the USB-1808 results they are really well linearly correlated, I mean the error is not an offset, the USB-1808 is always measuring about half the real value.
I tried to acquire the A, B and Z signals at 100kHz by means of the USB-1808 analog inputs and I attach an example of acquisition. I read that the quadrature encoder input are able to manage signal with minimum pulse width of 10 ns so honestly I don’t understand what is happening.
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Pietro89
We are currently using a USB-18080X board trying to read a linear encoder by means of the ENC0 input channel. We are experiencing a strange behaviour: when this encoder is moved statically by hand (for example 20 mm displacement), we are able to measure this displacement with the ENC0 signal correctly but when we put the linear encoder in our system in which it moves step-by-step measuring an intermittent incoming fuel volume, it seems we are able to follow the dynamics of the system but the overall measured displacement is lower than the real. We measure the real displacement with another board which has been widely validated and the consequent fuel volume measurement has been also validated independently. The particular behaviour is that, if we plot the real measurement and the USB-1808 results they are really well linearly correlated, I mean the error is not an offset, the USB-1808 is always measuring about half the real value.
I tried to acquire the A, B and Z signals at 100kHz by means of the USB-1808 analog inputs and I attach an example of acquisition. I read that the quadrature encoder input are able to manage signal with minimum pulse width of 10 ns so honestly I don’t understand what is happening.
I hope someone can help me.
Acquisition1.xlsx
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