4-20mA signal measurement

[DavidLee]

Dear Sirs,

There are some questions about 4-20mA signal acquisition and communication network wiring . This project will apply for a waterworks � SCADA system , this plant total have 102 flowmeters decentralized at different area , some are placed in a control room , some in the open air , each of them can output 4-20mA signal . The minimum distance between 2 meters is less than 20 m , and the maximum distance is 400 m .
How to link these meters to reduce the wiring ? Except mount the AI module near the meter , can introduce arbitrary power line from the meter to a control room ? Thanks .


David

[Brooks B.]

David:

My suggestion would be to put an FP-1601 Ethernet controller and an FP-AI-110 module (16-bit 4-20mA inputs & 50/60/500 Hz Filter) at each flowmeter. The filter on the AI module should take care of any power noise (60 Hz). Since it sounds like each of your flowmeters are pretty far apart, I think you will need a controller and module at every location. Each controller (FP-1601) will need an Ethernet connection and unique IP Address.

This would be the BEST Quality solution... I am thinking of a few BEST Cost solutions as well but have a lot more questions for you. Could you please submit a FieldPoint Email online via ni.com/ask and put my name - Brooks B - in the subject line? I need your company location/name and don't usually like to ask that i
nfo to be posted in a public forumn.

Sincerely,
Brooks B
Applications Engineer
National Instruments