I bought a new PROMASS Q 300 and am hoping to integrate the device using the HART protocol! Which kind of information do I need for the PV, SV, TV, and QV input values?

Flow Q&A

Expert’s answer: HART Communication- PROMASS Q 300

First of all, it’s good to know that you are already kinda using digital protocol! For sure, the HART communication has a lot of advantages simply not available when using analog communication. Realistically speaking, HART isn’t even a new protocol at all.  You already know the concept behind the HART communication, right? Let me just give a quick review for those who don’t.

Quick Review of Hart

When you read the HART information, you will find 4 different process variables on top of diagnostic and some other information. You need to set up the device and say which information you want in each of the 4 output values. They are called PV, ST, TV, and QV. What do they mean? The answer is pretty simple: Primary Value, Secondary Value, Tertiary Value, and Quaternary value.


Most field devices allow you to change this type of information through the display or Handheld. However, you some devices can have fixed values or have to have a different process like the HART server to change information. But this is not the case! The PROMASS Q with the transmitter 300 gives to you a large range of information options.

For example, when you set up the PV values you have a list with more than 13 options! To list briefly, some of the options included are Mass flow, volume flow, reference density, density, corrected volume flow, electronic temperature and so on. The SV, TV, and QV have fewer options than PV. Temperature, totalizer 1, 2, 3, density, and corrected volume flow are some of the the most common options.

Real Value

You’re gonna have a lot of information coming from the field! This is one of the benefits when you have a digital protocol instead of analog communication. The digital protocol provides you the chance to get 100% out of your field device. This can add real value to the application!

In a word, we have a couple articles talking about HART communication and you can check them out in the link below:

HART communication and Industrial IoT system

Your HART communicator and you

HART Communicator: When to Use

Video of the flow devices from Endress+Hauser: