Hello,
I have a 24 volt dc system. I want to monitor the system voltage by using a resistor. Ohms law says it should be 1.5k for a range of 6 = 4ma and 30 = 20 ma. When I go directly to ground it correctly measures the 16 ma at 24vdc. If I go to the analog input card it drops to 13.87 ma. Is this due to the internal resistor on the analog input card?
I have a 24 volt dc system. I want to monitor the system voltage by using a resistor. Ohms law says it should be 1.5k for a range of 6 = 4ma and 30 = 20 ma. When I go directly to ground it correctly measures the 16 ma at 24vdc. If I go to the analog input card it drops to 13.87 ma. Is this due to the internal resistor on the analog input card?