Two instrumemts, Same Loop

[EEENGRX]

I have an existing Radar Level transmitter on a Tank with a HART protocol. I want to hook up a pressure transmitter to same tank but on the already existing loop. what is the best way to run thisn connection as i think thisnis possible since they have same HART protocol.I need very clear ways to run this wiring.

 

[danw2]

Two approaches, either of which will make the cost of running another STP cable out the to the tank look cheap, by comparison.

- HART multidrop: Uses HART enabled AI card with pass through to pass the hart signals through to your asset management software.

- HART multiplexor: A HART mux switches from one HART device to another and maps the data it gets to registers in the mux. The registers are typically accessible via a Modbus/TPC server that your control system then reads the data from.

A 2nd cable is dirt bag simple in comparison. It's just 4-20mA, leave the HART alone.

 

[Taicho567]

I have an existing Radar Level transmitter on a Tank with a HART protocol. I want to hook up a pressure transmitter to same tank but on the already existing loop. what is the best way to run thisn connection as i think thisnis possible since they have same HART protocol.I need very clear ways to run this wiring.

I'm not sure I understand this question. Do you want to share the same loop? LT and PT give different value and reading from each other. Each of them has independent hard wire going to an individual AI channel at the DCS/PLC IO card so that each of the reading doesn't mix up with each other. Furthermore, each channel of the IO card can power up a single transmitter.

Mixing up two or more transmitters in one loop - I'm not sure if this is possible.

 

[btrueblood]

Taicho, it's possible if only using the HART or similar digital communication over the loop, rather than the analog value of the current (standard 4-20ma output)