Issue
Can a 7740 read 4 to 20 milliamp input?
Environment
I/NET site
Cause
Some sensors will only output a 4-20ma signal and the controller must be able to read it in order to display the sensor values.
Resolution
Although the controller is calibrated to read 1 to 5 volts, a voltage sensing resistor can be added to read 4 to 20 milliamps. Refer to TCON 092 for details.