fieldbus & power lines

[fjmezano]

I need to know if there's any standard separation between AC power lines and the fielbus trunk.

I have a radar level xmtr 5401 and it has no communication with DeltaV but the trunk is beside a few 440VAC power line. so, could you provide me this information, or where can i get it from?

[rezabejd]

I don't believe there is a "standard" separation per se. For "long" parallel runs, I think 10 feet / 3 meters is not uncommon for all DC circuits. Our cable tray have both FF and conventional twisted pair 4-20 mA run together, so what's good for one must be good for the other.

We do have a number of instances where high AC voltage feeds (480 to 5 KV) cross the DC tray at right angles and have seen no ill effects.

Since FF is a digital signal, it should be more noise immune. I know it has been tested in some high noise applications. I would look into other possible causes for the failure to communicate, like too little voltage, wrong polarity, improper shield terminations, etc.

[Heather Santos]

Are there other devices on the same trunk?