HART communicators offer intelligent device management (IDM). On the other hand, the Industrial Internet of Things (IIoT) usually means a system with SMART devices connected to each other and a cognitive platform. These devices send data through digital protocols to the platform for analysis. The article talks about such communicators and applications.

The cognitive platform uses all the data from the SMART devices both to monitor the process conditions and to learn. It can help you avoid future problems with your devices and improve your process.

Also, we now have plant information management systems (PIMS) with cloud options. That means you can store your data remotely and even have off-site specialists reviewing your devices and sending you reports about their performance.


Isolated USB HART Modem

Connecting a HART device to an IIoT platform

There are many ways to implement HART devices in an IIoT platform. Let’s start with a common scenario, where you have HART devices connected to the control system using an analog 4-20 mA connection.


Without digital connections between the devices and the system, you need another way to pull your field data. In this article, we discuss the usage of a wireless solution versus a multiplexer or programmable logic controller (PLC) card.

Wireless connection

If you have an analog connection on your HART field devices, then consider a wireless solution. It practically clicks into your system with hardly any reworking of your structure, so it’s super easy. To do this, you’ll need to install a wireless adapter in your field device. The adapter will read the HART data and send everything to the gateway.

The gateway uses an Ethernet protocol to send the data to the system. Once the data gets there, you can integrate it into an archive. Later, that data can go into a PIMS.

Before you get all excited about your new wireless gizmo, I’ll warn you that it costs more per point than the PLC card but less than the multiplexer. Let’s go to the next one so you can cool off and consider your alternatives.

HART multiplexer

A HART multiplexer can give you the same data as a wireless connection. On the downside, the cost of implementation and the number of hands involved make it an expensive choice.

Courtesy of FieldComm Group

I had a bad experience with a multiplexer once. The control system had interference between the field devices and the plant asset management system. We had to install barriers to get into the control system, but it took us a while to find that workaround. If you know of any good points to a multiplexer worth mentioning, hit me up.

PLC card

Depending on your control system, you might be able to upgrade your input card with a HART card. In my opinion, it’s not the best choice, but let me tell you why. You may find a better way, and if you do, be sure to tell us about it.

To read your diagnostics through the control system, you may have to go brand-specific on your devices and software. Many control systems on the market have external PIMS solutions that can’t access data from other brands. If you’re already a loyalist for a certain company, then you’re gold! But if you have a mixed family, you’re out in the cold. Again.

On the positive side, this can cost less, depending on your system. Of course, if you have a really old system, it may cost more to upgrade the whole thing than to go with a wireless solution or multiplexer. You’ll have to do the math on that.


HART devices provide enough data to support PIMS in IIoT solutions. You just have to find a way to access that data. Open protocols and standardized solutions are crucial to expanding connectivity across various brands of devices and systems.

While some people talk about IIoT like it’s still in the future, the technology is already here. Several companies have developed gateways and cloud storage for it, and field devices already meet the data requirements. The main reason why it is not the norm is that most major companies designed their infrastructure years or decades ago, and a complete restructuring would be too expensive.

To know more about such products, you get in touch with our engineers!

Recommended articles

HART handheld communicator: setup, applications, and use guide

Analytics Articles Control System Industry 4.0 Wireless

Product Review: Endress+Hauser Field Xpert SMT70

Asset Management Featured Product Review