Any manufacturer who implements HART (a communications protocol) in his field instruments provides a "Device Descriptor" (DD) file speciric for that HART enabled device (or sometimes a series of devices).
The device descriptor file works in HART enabled communicators (like the HART 275 communicator, or Siemsens PDM Windows software) to access all of the parameters in the HART field device, not just the 'generic' HART parameters.
Either once or twice a year, the HART foundation publishes a big list of all the Hart devices and their DD's. In early versions of the Hart handheld communicator, the handheld had to be sent back to the factory to have DD's added to it. The HART 275 hand held communicator was recently replaced by the 375 (?). I'm not sure if the 375 has capabilities of having DDs added without being returned for service, but I suspect it does.
In my experience, the DDs are usually provided on the manufacturers' web site. I downloaded a Siemens level sensor DD the other day and installed it in their PDM software.
In any case, they're not hard to get ahold of, because the vendors want to use what they've spent lots of money developing. I've never heard of any manufacturer charging money for a DD.
Some devices can be setup using the "generic" HART commands/paramters, which I think are basic parameters like
LRV (lower range value)
URV (Upper Range Value)
tag name and
engineering units
Devices like Coriolis meters almost always have to have the DD to access the secondary and tertiary variablesand the more complex setups. I've setup any number of pressure transmitters without the DDs because the few 'generic' HART parameters were sufficient.
It appears that the customer (in the original post) wants to avoid chasing down the DD's himself.
Dan