Expert’s answer: Do you need to do a loop test to check communication?
Not really. You can skip the old loop test with the 4-20mA generator. If you have a digital network and the device can communicate with the control system, then you’re good to go.
However, you need to pull the process values from the field into the control system, and you can simulate that. You can use the device display, handheld, or laptop to do the simulation. Just create an output process value and confirm that the value made it to the control system.
For more information, check the links below:
I’m working in a plant startup, and I need to do the test on all our 4-20 mA field devices. Do I need to?
I have 10 field flow meters from Yokogawa, and I’d like to do tests directly on the display, instead of a field communicator. Could you give me the step by step?