mjp123gp
Member
While troubleshooting an issue with an analog input card the other day, I removed the terminal block from the input card. Looking at the values in the program, everything went high to a value just over the high scaled value. Since we have the input range set to 0-20mA and all of our scaling is 4-20mA I would expect the input value to go low or negative. I've checked the other settings for the card but can't figure out why it did this. I thought it may have been an issue with the module so I swapped it with a new one and it did the same thing. You can see in the attached pic that channel 2 and 3 are scaled 4-20mA / 0-750 but the actual value show 777. In this pic, all wiring has been removed from the card so there should be 0mA to each input.
Can someone explain please why it does this?
Can someone explain please why it does this?