HART help!!!

Hello everyone, as always great discussions everytime I stop through this site.

We are currently reviewing several HART communications software packages. One of them is Rosemount's AMS, another is ABB's SmartVision, and the last is one by Siemens. None of the 3 seems to be able to communicate with ALL HART devices very well. And all 3 of them have their own way of being a cash cow. Like the AMS software, you purchase tags like 25 at a time, and you can only support the number of devices per tags in which you purchase. I just don't like the idea of carrying a laptop to a device, especially with our wet industrial environment. Well I suppose though you could go to the PLC racks, where it's a bit safer.

The only other alternative is obviously the HART 275 hand held communicator. HART says that it will communicate with all HART devices, is this everyone's experience??? I just don't want to make the purchase and discover that there is a HART transmitter it won't talk to because I didn't buy ABB's communicator or something. HART does publish a list of manufacturers in which it will work, I just want to see what people's experiences are with the handheld 275.

Thanks for any input!!

Greg

After re-reading this about 20-times, make that 30-times... I wonder, are you talking about a Brand called HART or is that an acronym for something?

I really wish that everyone would quit assuming that everyone knows about all of the brands, brand-specific words and acronyms that they happen to know!

One of the most frustrating things for us (that is, for the irregulars, and what not) is see a poorly constructed question.

Blow it off, Greg...Don't take it personnaly!
If you are going to assume anything, assume that we don't know what you are talking about when you post a question!



I'm not really familiar with the HART Brand, but I have used HART-Brand stuff many years ago.

I've always believed that the very idea of having to PAY for TAGS is OUTRAGEOUS!!!

If it is the case that you have to PAY for each teeny-tiny group of TAGS... BLOW THAT MANUFACTURER OFF!

This sounds to me like a case of "Newer, Fancier, Spendier... and getting Less, and Less and Less!"

Jumping onto "The Latest and Greatest" ain't necessarily smart.

Don't forget, in fact, NEVER, NEVER, NEVER FORGET (this is one of those cases where it's OK to say "NEVER")... manufacturers are really only interested in getting as much money from you as they can!

Certainly, that's Capitalism, in one of it's truest forms... but that doesn't mean you have to buy into it. CAVIAT EMPTOR! (Let the Buyer Beware!)

Now, I'm a little (a lot) confused about your current configuration... on the one-hand I get the impression that all of your field devices are HART (Is that the brand-name, or an acronym - if it's an acronym, for what?). On the other-hand, not.

Please clarify your current situation and what you are trying to handle.

25 TAGS? Jezzzz! OUTRAGEOUS!

I have found that using "older" methods (which can indeed be more cost-effective, I might add) with more careful planning, provides more than adequate control.

So, please clarify!

I think its a form of communication protocol used with devices in the industrial environment.
http://www.hartcomm.org/

If this is way off base please let me know.

Terry. From memory HART is a communication protocol. Stands for highway addressable remote transmitter (or maybe transducer).
Many manufactures make sensors with inbuilt HART cooms. Regards Alan Case

Yes, HART is a communications protocol used to communicate with field instrumentation devices......Sorry, I thought it was a large enough industry term everyone in the I&C field was familiar with....It rides on the 4-20mA loop using FSK (frequency shift keying), to communicate with the device......in turn used to range and set up transmitters or any device that communicates via the HART protocol.

Thanks

Greg

What's the "I&C field"?...

(only kidding)

beerchug

-Eric

Greg I have two 275 HART programmers on my sight and yes they will talk to all HART instruments. The 275s menu is far superior to earlier models. Quite easy to carry around
HART stands for Highway Accessible Remote Transducer.
Try www.emerson.com and there is a a good tutorial on it on the site.

HART is also not the latest and greatest. In fact it being superseeded as we speak, to be replaced by Foundation Fieldbus as hopefully a universal standard for instrument and device communications. It is being backed by Emerson ( ex Fisher Rosemount and Yokogowa so far )

Greg, we also have AMS database. We have the 1000 plus tag license as we have some 800 odd "smart" HART compatable instruments on our plant. AMS came about roughly in 1996. We disconnected ours from our DCS network about two years ago. AMS was an excellent tool in theory and sometimes it worked. On one occasion I standardised a density transmitter from the workshop, but it had least priority on the DCS network so it did not get updated fast enough.

We disconnected it from the network and still use it as database and calibration tool for our instrument cals. You simply need a HART modom for your AMS pc and conected you instrument to it. It prompts you to apply your setpoint pressures and it knows how far off scale it is. This means no one can "fudge" cal sheets as it is all stored on the database.

I have written quite a bit, let me know if you need to know more in better detail.

Just some thoughts from your questions about HART... hope some of it's
helpful.

HART instruments are not "smart" in the sense that they store their
communication info on-board themselves. The handheld is the "smart"
device that must be able to talk with that specific instrument. Every
single field instrument will have a unique HART device description, called a
"ddl", that must be loaded on the HART handheld. This is not just for
every manufacturer, say Rosemount, Yokogawa, and Honeywell for
instance, but every single Rosemount transmitter must have a unique "ddl"
loaded on the handheld, and every Yokogawa transmitter has a unique "ddl",
and every Honeywell transmitter has a unique "ddl" that must be loaded
on the handheld in order for you to communicate.

Back when HART was in it's early stages, the HART handheld had a
limited amount of memory capacity, say 1 MB ( I don't remember exactly).
That meant you had to pick the devices you wanted to use from the master
HART list and have just those device "ddl's" loaded on your handheld(s).
It was common for people to have multiple handhelds and rotate them
back to a factory service dept. once a year for updating. Today the new
HART handhelds have much more memory on-board, at least 12 MB at this
point, so you can get nearly every manufacturer's transmitter ddl's on
the newest handhelds.

I am not as familar with the AMS-type software, but I know that the
HART transmitters have not changed the way they communicate overnight.
That means that the AMS software must have every single HART-capable
device "ddl" loaded internally somewhere. There is no such thing as a
generic HART ddl that can extract every data point out of every HART
transmitter unless it uses the device-specific "ddl".

So - there are two cases in my mind - either the software uses a
generic "ddl" that will limit your capabilities of getting advanced
diagnostic data out of the transmitter (if that's the case then why bother
buying the software?) OR the software contains all existing device
"ddl's" and probably has to be upgraded periodically in the future to keep
up with the newest devices.

Another thing to consider is how are you going to access the
instruments? AMS software usually runs on a PC that is separate from the control
system. Are you using a PLC? A DCS? Most likely you can't access all
the field instruments through those systems. Therefore, you may need
to "strip" the HART signals off the analog 4-20 mA signals. You may
want to contact someone such as MTL to check our their hardware for HART.
MTL's hardware combined with the AMS software is a complete package.
The MTL 4700-series, for example, matches up with your DCS or PLC
hardware to pass along the 4-20 mA signals, then also allows the PC running
AMS to communicate directly with the HART instruments. MTL is not the
only manufacturer of such equipment.

I have no idea what your facility has, so I'm just throwing out ideas.
Good luck.

Labingstone you said

"but every single Rosemount transmitter must have a unique "ddl"
loaded on the handheld, and every Yokogawa transmitter has a unique "ddl",
and every Honeywell transmitter has a unique "ddl" that must be loaded
on the handheld in order for you to communicate."

a HART 275 has this ddl preloaded so you can identify which brand of instrument you want to talk to.

A true hart instrument instrument is "smart" in that it can store a multitude of data info, hence the term smart. For instance a "smart" valtek" positioner for a choke valve will know what postion it will should be in via the signal from control system ie DCS 4-20ma but it will send a digital signal back over the dcs indicating what TRUE position it is in, plus a multitude of other info. It knows what position it is by its intial cal setup. It can perform a 3000 point cal in a few seconds that is far superior than anything me and you could cal to to in a million years. It then refers to this cal graph/scale to worj out its true position to what input it is given. This is helpful in our process when huge scale build up prevents valve from fully closing, thus gives feedback to indicate scale build up and maintenance required.
This i s one example.