1794-IE8 Fast Analog Input Module

Dear Members;

We have Fluke 754 hart communicator. We have wired up three transmitters of Rosemount Model C3051 with this input module. But when i connected Hart it shows NO HART DEVICE FOUND.
while when we connect these transmitters to other analog input module which is not Fast Analog the hart reads the data.

Is it possible to read the data of transmitters at HART which is connected with Fast Analog Input?

what property of module i change?

Please help me

Regards

The 1794-IE8 is considered a "high density" and "non-isolated" analog input module, which also has a faster A/D converter because it's a relatively newer design than the original 1994-vintage 1794-IF4.

Are you using the ordinary 1794-IE8, or the 1794-IE8H, which has a built-in HART modem ?

Which exact part numbers of analog input modules work correctly with your external HART Communicator ?

If isolation between current-loop channels is a concern, of course go ahead and remove all but one of the devices from the module connections and see if your HART modem works on just one loop.

The input resistance of the 1794-IE8 is specified as 238 ohms. It is my understanding that a HART calibrator or modem should be put in series with a loop that has less then 250 ohms, instead of in parallel.

It is my understanding that the 1794-IE8H (with the built in HART modem) has an input resistance of 278 ohms, which makes it appropriate for the connection of a handheld like the Fluke 754 in parallel.

The Hart spec says minimum 230 Ohms of loop resistance; resistor goes in series in the loop. Wire resistance and AI input resistance count, as well.

If the AI has an integrated Hart modem, the Hart spec allows for a primary and a secondary Hart master. The handheld acts as a Hart master and an AI Hart modem would be a Hart master as well, so the Hart masters should play nice together.

One would think a Hart AI card would have an input dropping resistor that is suitable for Hart comm, but I’m too to check the product manual.

Hart AI threads are scarce. Please help us all and post your findings.

turbohamad said:

Dear Members;

We have Fluke 754 hart communicator. We have wired up three transmitters of Rosemount Model C3051 with this input module. But when i connected Hart it shows NO HART DEVICE FOUND.
while when we connect these transmitters to other analog input module which is not Fast Analog the hart reads the data.

Is it possible to read the data of transmitters at HART which is connected with Fast Analog Input?

what property of module i change?

Please help me

Regards

Click to expand...

Spectrum Controls has a HART PointIO module that works pretty well.

I’ve never had a problem with that, with over 100 new devices during the last couple years.