Analog transducer inputs

[Ralphie]

Hello,

I am working with an expanded V130 and a 570. 12 bit analog inputs. I have the displays all working, I am displaying a height measurement from 0 - 5 inches with a linear pot that has a five inch stroke. Trying to eliminate the mechanical connection, I have ordered a analog output ultrasonic transducer.

I think because of the way the machine works, my analog signals on these two types of sensors will end up being opposite. When the pot reads 5 inches, I think the transducer will read 0. Is there a way in the plc to invert this input and still have it display correctly? I need them to read the same height.

I tried to make a change in the linearization parameters with not luck, and have searched the help section to look for a way to invert an input with no luck.

Thanks Ahead

[Joe Tauser]

First, verify which type of analog input you are using. You didn't say which V130 and which snap IO you are using, and they can be either 10 or 14 bit, but not 12. That makes a big difference in the X1 and X2 values. Also, is your transducer outputting 0-10V or 4-20 mA?

Reverse the X1 and X2 parameters in the linearization block to reverse the scaling. Let's say you have 14 bit analog on a 0-10V input signal = 0-5".

X1 = 0

X2 = 16384

Y1 = 0

Y2 = 5000 (implied 5.000)

For 0-10V = 5-0":

X1 = 16384

X2 = 0

Y1 = 0

Y2 = 5000

Joe T.

[Ralphie]

First, verify which type of analog input you are using. You didn't say which V130 and which snap IO you are using, and they can be either 10 or 14 bit, but not 12. That makes a big difference in the X1 and X2 values. Also, is your transducer outputting 0-10V or 4-20 mA?

Reverse the X1 and X2 parameters in the linearization block to reverse the scaling. Let's say you have 14 bit analog on a 0-10V input signal = 0-5".

X1 = 0

X2 = 16384

Y1 = 0

Y2 = 5000 (implied 5.000)

For 0-10V = 5-0":

X1 = 16384

X2 = 0

Y1 = 0

Y2 = 5000

Joe T.

Joe,

Thank you for the information, I just wanted to let you know that on the V130 I am sending the input to a I/O-A14-AO2 expansion module. The regular V130 does as you say only have ten bit inputs, that why we added the other in order to have better resolution on the distance measurement and for a load cell input. I am only working with the 0-10v values. I figured this should be a simple thing to do with the Unitronics, I don't know why I didn't try changing the linearization numbers. I am new to Unitronics and amazed at all the stuff this little package can do.

Thanks Again