Using an MTL 7706+ Barrier eith HART

A

Thread Starter

Allan Doc

Can the MTL 7706+ barrier be used with HART? This barrier states that it is an analogue barrier but it seems to be used with HART transmitters in my workplace.
 
Your co-workers and colleagues are the people who can tell you whether it works or not.

It should work. HART is an FSK signal superimposed on the 4-20mA DC signal (the analog part).

The two FSK frequencies (tones that represent a logic one or logic zero) are 1200Hz and 2200Hz.

The MTL 7706+ spec sheet at
http://www.mtl-inst.com/images/uploads/datasheets/7700/MTL7700_active_barriers.pdf
claims HART compatibility by

- stating "MTL7706+ for 'smart' 2-wire 4/20mA transmitters" (HART is supposedly 'smart') and

- stating "the MTL7706+ will pass incoming communication signals up to 10kHz from a ‘smart’ transmitter"

Since 1200Hz and 2200Hz are less than the 10KHz limit, the HART FSK signal should pass through the barrier.

But why don't you ask the guys who drag the HART communicator to the marshaling panel? They'll tell you whether it works or not.

(remove the space in the URL)
 
Top