One HART Communicator to communicate with different manufacturers terminal


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Good evening,

How can we puchase HART handheld terminal? We have three different manufactures Smart Type Transmitte. Can we purchase only one manufacture HART terminal for configure different manufacture transmitter? What points need to remember for procurement of HART communicator? What are the reputed manufactures for HART communicator? Can someone provide specification for the same?
I've found that virtually each firmware rev of each transmitter model needs its own DD, device descriptor, a file specific to the instrument/device, in a HART communicator.

So you need to find out if the HART communicator that you purchase has the DD, or its version of a DD (Meriam calls them DOFs) for whatever devices you have.

All HART devices are supposed to respond to changes in the 7 or 8 generic parameters like tag, LRV, URV, units.
Yes. By definition every revision of every type of HART device has a unique DD file. This is because by definition each revision of a HART device has some new feature. It needs a new DD file so the device manufacturer can describe how this feature is communicated and how it shall be displayed in the system.

When the new revision DD is added, the old files are not touched, they continue to work as is. What is running is not upset. Old and new versions can coexist.

When you buy a handheld field communicator such as the Emerson 475 it comes with most files pre-loaded. However, new device revisions become available every month. If you purchase new device months later, you must load the DD file for it.

All devices support Universal Commands so you are able to get this basic information even without DD:

-Write Protection Status
-Final Assembly Serial Number
-PV unit
-PV value in engineering unit
-PV value in percent of range
-Upper Range Limit (URL)
-Lower Range Limit (LRL)
-Minimum Span
-Transfer function (Linear/Square root)
-Upper Range Value (URV, "20 mA")
-Lower Range Value (LRV, "4 mA")
-Damping time constant
-Sensor serial number
-Output current value

However, advanced setup and advanced diagnostics requires DD

Note, that DD (Device Description) has been renamed "EDDL" (Electronic Device Description Language).

To learn more about HART take a look at the yellow book "Fieldbuses for Process Control: Engineering, Operation, and Maintenance" buy online:

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