I'm adding a Hart Tri-Loop to my GE Mark VIe control and having problems. The transmitter from which I need to extract values is a Rosemount 3095MV, the fuel gas mass flow transmitter common to most GE 7FA turbines. The tri loop is reporting a "Burst Mode Message Timeout" error. At the same time, I am having lots of trouble talking to the 3095 with my handheld 375 Hart communicator. These problems go away if I sever the connection to the Mark VIe and power the transmitter directly. Any ideas?

 

Severing the connection to the Mark VIe and powering it remotely changes the cabling, the power supply and the input resistance.

I suspect that there's sufficient loop resistance if HART works at all. But better results by changing cabling and a power supply could be telling you that the HART signal is being affected by noise: induced noise in the cabling or power supply ripple or capacity. Is the cable shield connected? at one end only? I don't suppose electrical noise is likely around a Mark VIe.

Emerson specs the max power supply AC noise at 0.2 volts peak to peak. Or if you've powered the output of the Triloops from a different power supply than that which powers the 3051 you could have ground loop noise.

I don't recall the HART symptoms if power supply voltage is insufficient to drive the loop current through the loop resistance (loop current will not achieve max 20ma). You've added a device - the TriLoop. Is the power supply capacity marginal with the addition? Flakey HART with low voltage?

 

Emerson's supplement for Fieldvue HART defines "Burst mode message timeout" as
Burst mode message timeout Tri-Loop not receiving burst command "3".

So what could cause the the burst mode message to go missing altogether?

- 3051 not configured for burst mode

- I/S barrier or isolator strips HART off the loop signal

- the message could be too broken up due to noise to be recognizable. signal/noise ratio too low.

- burst mode input not wired correctly, insufficient loop resistance for HART

 

HART Tri loop

I have limited experience in rosemount flow meters, but i believe that it is not a problem with mark VIe. the "burst mode message time out" is coming because the 3095MV is not configured to transmit in burst mode. you must configure the "burst mode" rate-3 in the 3095MV transmitter. the Tri Loop has an excellent manual which i believe gives step by step guide of how to commission the TRI loop with 3095MV. if i am able to dig out the manual i will post it here. if you have already done this check the scalings and units in both the tri loop and the 3095MV. they must match for a proper communication. check also the field connections, as per the drawing in the manual. it is quite different from the conventional 4-20ma transmitter.

 

Wow, emerson seems to have uploaded all their manuals online , this is the manual i was talking about
http://www.2shared.com/document/qPN-P1lA/00809-0100-4754.html

it details how to commission a tri hart with a 3095MV mass flow meter. you have all the information you need in here.

you can also download this from

http://www2.emersonprocess.com/en-US/brands/rosemount/Accessories/333/Pages/index.aspx

then go to manuals and guides and down load the manual.

 

Which terminal board and which terminals is the device connected to?

 

From my experience with our 3095MV transmitters you cannot configure the parameters with a 375 communicator. You need to use Engineering assistant software (sold by Rosemount). We have had to have a local Rosemount Rep come to site with his laptop and software as I believe the 375 can only be used to view data and not change much.

I believe the manual for the 333 Tri-Loop only shows how to configure the 3095MV using Engineering Assistant software not the 375.

 

No wonder the Emerson guy comes out to set up a Triloop. Look at the PC requirements (program comes on floppies) [from Triloop 333 manual (Rev BB) from the Emerson site].

Minimum Equipment and Software
- MS-DOS based 386 computer or above
- MS DOS® 5.0 or higher
- 640K base RAM with 8 MB extended
- Microsoft® Windows® 3.1, Windows for Workgroups 3.11, or
Windows 95
- Mouse or other pointing device (optional)
- Color computer display (optional)
- HART Tri-Loop Configurator Software, HART modem, set of
modem cables

The manual does not mention configuring the Triloop's settings with a HART handheld, that's what the DOS/legacy Windows app is all about.

 

MPAC is right

1. Install the MV Engineering Assistant powered by AMS on a NotePC

2. Run Engineering Assistant,will find HART Modem1 and 3095 device

3. right click on 3095->configuration properties

4. First,HART->Burst mode=Off,then check:
Basic Setup/DP/SP/Pt snse/Process input/Analog Output

5. Hart Tri-Loop config:
right click on 3095->SNAP-ON/Linked Apps->MV Eng.. Ass->Steam(if used for Steam)->Superheated&Saturated Steam->Open current file->check config right:

Orifice plate: we checked the primary element minimum diameter(2.067) was wrong, I have changed to 2.6075, then Next to modify the others parameter, usually the default parameter need modify according to actual pressure range and temperature range.

go back 3095 device setup, change Burst mode=ON

 

Running the Engineer assistant
right click on Tri-Loop device->Configuration properties
modify channel1 to 3
our tri-loop 333's parameter:
Channel 1: SV, inh2o, 250.0~ -250.0, YES
Channel 2: TV, psi, 800.0 ~ 0.5, YES
Channel 3: QV, degF, 1510.0~ -299.0, YES

 

> Which terminal board and which terminals is the device connected to?

CSA, the Primary variable comes to the Mark V at <S>TBQC 73 and 71. I send the Tri-Loop outputs to the same term board, pins 67/65, 68/69, and 79/77.

 

David, Process Value, MPAC, and Ray2000:

looks like the problem might actually be within the 3095MV itself. I finally got back to this project (plant manager won't let me touch fuel flow while the plant is running, what a coward...) and while I can talk to another 3095 on site with Engineering Assistant, nothing I do will allow me to talk with this one. Guess I'll have to get Emerson on the phone.

Thank you all for taking the time to help me.

 

> CSA, the Primary variable comes to the Mark V at ....

I'm missing something real fundamental here....

The title of this thread is "Hart Tri-Loop not working with GE Mark VIe" and John Gardner is the originator.

Now, John Gardner is replying saying the device is connected to four inputs of a <b>Mark V</b>.

All I can say is, "Huh?"

 

TRI-LOOP have an power supply wire (HART TL1 BURST+ and HART TL1 BURST-) and three output wires (Hart Tl1~3, 4~20mA, gas flow-inh2o, gas pressure - psi, gas temperature - degF) connected to the MKV terminal board.

 

Yes; if one is using a Tri-Loop with a <b>Mark V</b> an external power supply is likely required. The <b>Mark V</b> has known issues with some transmitters; the Tri-Loop is most likely in this group of transmitters.

But, this thread was started for issues with a <b>Mark VIe</b>.

Or at least that's what was in the original thread from the original poster.

I'm <b>SOOOOOOO</b> confused!

 

Just for example&#65288;Use MarkVI&#65292;No Mark VIe!!! &#65289;&#65306;<pre>
MKVI Control Panel HART TRI-LOOP MODULE
Location Wire No. Location
1A2 TBAI 33,34 4170/4171 HART Tl1-1+,Tl1-1-(96NM-TL1-CH1)
1A3 TBAI 33,34 4172/4173 HART Tl1-2+,Tl1-2-(96NM-TL1-CH2)
1A2 TBAI 37,38 4174&#12289;4175 HART Tl1-3+,Tl1-3-(96NM-TL1-CH3)

1A3 TBAI 37,38 4176&#12289;4177 HART Tl1 BURST+,-(96NM-1+&#65292;-)
TBAI 33,34</pre>

 

Sorry for the confusion. It's a hybrid system: a "Mark VIe conversion". This means the old <D> core goes away, and while Mark VI packs replace the <R>, <S>,<T>, and <C> cores, the I/O terminal boards from the Mark V remain. It was a Mark V for long enough that we still call it that by habit. Heck even GE doesn't seem to be consistent when referring to it!

Now that it's working, here's the skinny: the 3095MV requires a loop resistance of 250-1000 ohms. The burden resistor on the Mark V I/O boards is only 100 ohms. I added an external 250 ohms in series with the signal, no luck. I doubled that, and Viola! The permanent fix was to add a 680 ohm resistor (that's what I had in the goody box) in series, and take the Burst Input for the Tri Loop from the instrument side of that resistor.

 

> Sorry for the confusion. It's a hybrid system: a "Mark VIe conversion".

GE's pretty consistent in referring to that as a Mark Ve.

 

>> Sorry for the confusion. It's a hybrid system: a "Mark VIe conversion".

> GE's pretty consistent in referring to that as a Mark Ve.

Actually this is something new. There are a few additional boards that get replaced with packs, which differentiates this from a V-to-Ve upgrade. On site we jokingly refer to it as a "Mark 5.5e". We're only the second site to get this upgrade; the first one besides the test site. GE gave us a list showing the difference, I'll dig it up and see if it was GE Confidential.

 

Found the drawing. I can't share it (it's labeled "proprietary and confidential"), but here are the additional card changes that define the Ve to VIe migration: in <P> the three TCEA cards are replaced with PMVP's, and in <QD1>, <QD2>, and <CD> each TCDA is replaced by a PMVD.