I have successfully installed and am using an Allen Bradley 1746-NI8 Analog Input Module.

If the module receives an out-of-range error it faults the processor.

What can I do to avoid the processor fault. I can live with the out-of-range error, because they are caused by operator mistakes.

 

You can create a new ladder which will be your fault routine. Look under controller properties so find the pointer that sets the routing that runs when you have a fault.

Then in this routine set the value to an acceptable value and return to the normal operation.

Carfully consider the safety aspect of setting this value.

There are many other things you could do! how is the operator inputting this value. From a potentiometer ? Then you could simply limit the upper value ( or lower ) with a rung of code
Use the following line of code.
grt analogvalue max move max analogvalue

Where analogvalue is the input from the card.

Hope this helps

 

My guess is you are using a SCP instruction, to prevent the out of range stopping the processor put OTU (Unlatch) S:5/0 on a rung at the very end of program file 2, this will clear the maths overflow before the end of the scan.

 

I don't believe that out of range errors fault the processor. Its possible that the math you are doing on the analog input value results in a math error that does cause the fault. put an otu S5/2 at the very end of your program to stop this.

Bob Peterson