HART Help?

[TwoBlocked]

We got some hit and miss 375 and 475 communicators. Sometimes they are able to access the parameters we need and sometimes not. Then sometimes you can find the charger when the battery is dead, and sometimes you can't.

I understand you can use a laptop to communicate with devices and change the needed parameters if you have the "right stuff". Thing is, I don't know what the "right stuff" is nor how it works together. I believe I have PACTWARE installed on my field laptop. And I do have a Microlink HART Protocol Modem. There's probably some DMT files stashed on the laptop somewhere, too.

Any help would be appreciated.

 

[DBill64]

You're going to also want a 250 ohm resistor (I use the 541-RN65E2500BB14-ND off of Digikey, but any 250 ohm resistor should be sufficient) and possibly the drivers required for the specific device you want to communicate with over PACTWARE. I do not have the exact modem you do, but the configuration of resistor, modem, and instrument should be the same as my ProComSol HM-USB-ISO. With modem already connected to PC; connecting should go as follows: put 250 Ohm resistor in series with the positive or negative leg of your loop > hook up the modem clips to both sides of the resistor > energize instrument loop. Now with PACTWARE you may need specific drivers for the device you intend to communicate with, but you may be able to utilize the Generic HART DTM driver it comes with. What devices are you trying to communicate with?

 

[TwoBlocked]

Thanks, Bill. I've learned a great deal since my original post. First, was able to find a charger for the 475 and get it running. Second, updated PactWare on my laptop, and yes, have the generic DTM file. Have not used it yet b/c of the working 475. Third, found out that PactWare uses only DTM files, while Emerson devices, such as Rosemount use DD files. Emerson's 475 Hart communicator works with devices that use either DTM or DD files. Used the 475 for some devices. Downloaded Emerson's AMS configurator software for non-guided radar tank level transmitters made by Rosemount.

And yep, I know about the 250 ohm resistor requirement. (Ended up putting four 1,000 ohm resistors in parallel by twisting the leads together, soldering them, covering with heat shrink, and putting them in triple wagos with a jumper hanging out.) THANKS!