My plant recently installed a HART multiplexer to read the field information. I know that I can have more process values coming from the devices, which kind of process variable can read remote as well as diagnostic?
Expert’s answer: HART Values and diagnostic – PROMASS Q 500
I’m gonna assume you have analog cards, and you are using the HART multiplexer to read the diagnostic and other information coming from the field? Right? On the other hand, there are also multiplexers where you can integrate the information into the SCADA system using other protocols. I’m gonna cover both here.
Gotta have HART
Okay, so you are reading the HART information from the field devices through a multiplexer? You will probably have a plant asset management system reading this information. In that case, you are going to need the device descriptions files (DD’s) or depending on the platform the DTMs. These files are responsible for translating the information from the field and having it show up in the right place for you to read.
HART values usually are read when you have a HART input in your control system. Another option is to have a WirelessHART adapter. The WirelessHart adapter will be responsible for reading the information from the field and sending it to the control system. You can have 4 HART values. The values are Primary value (PV), Secondary value (SV), Tertiary value (TV), and quaternary values (QV). Usually, the device comes with a standard value for each option. So feel free to double check in the technical manual. However, you can change this information using a Handheld, PAM system or in display.
PROMASS Q 500
The PV of PROMASS Q 500 provides more options than others. Options like mass flow, volume flow, corrected volume flow, density, temperature and more. Others on the market bring good options as well, but fewer than PV. The complete list is available in the technical manual.
Through the HART communication you can read all the diagnostic information from the device. In this model, you can run the Heartbeat Technology and find out the health of the sensor and the electronic. If your multiplexer offers an integration into the SCADA using an OPC, or other protocol,you can read all HART values there.