The purpose of this article is to explain which hardware and configuration are essential for a successful HART implementation using Rheonics Sensors. Rheonics inline process density meter and process viscometers come with native support for HART.

TABLE OF CONTENTS

• 1. When I order the sensor, Have I already purchased HART?
• 2. Can I order HART after a sensor is shipped?
• 3. Cabling
• 4. HART Communication devices.
  • 4.1. PLC
  • 4.2. DCS
  • 4.3.Field Communicator
• 5. Which variables are offered by Rheonics for the HART protocol?
• 6. References

1. When I order the sensor, Have I already purchased HART?

No, HART is not enabled by default on Rheonics Sensors. You will need to select the HART communication protocol during ordering. To order the HART communication protocol remember to check the C8-HART option on the RFQ page. HART is available on all Rheonics viscosity and density meters. The video below shows the steps to be followed to add HART to the device configuration:

2. Can I order HART after a sensor is shipped?

Yes, communication protocols like HART can be ordered later. It incurs an additional remote service fee. Contact Rheonics sales to order giving your sensor serial number.

3. Cabling

In this article, we are explaining which hardware and configuration are essential for a successful HART implementation. Rheonics Sensors with HART protocol enabled will allow communication through 2-wire using the same channel as the 4-20mA signal. The HART protocol requires a minimum of 250Ω resistance on the data channel to ensure reliable communication. This is an essential requirement for successful HART configuration and should be taken into consideration when designing the wiring for the device.  

It is recommended to use cable 16AWG or 18 AWG for wiring the analog outputs from channel 1 from the Rheonics SME.

4. HART Communication devices.

4.1. PLC

A Programmable Logic Controller (PLC) is a digital computer that uses inputs and outputs to automate industrial processes. HART communication requires special hardware, which is not available in every analog card used in PLCs. Therefore, it is important to select the right analog card when the application requires HART communication.

4.2. DCS

One of the key advantages of using DCS for HART devices is the ability to access detailed information about the devices. DCS can read and interpret the digital data transmitted by HART devices, providing valuable insights into their health, status, and diagnostics. This information can be used for predictive maintenance, troubleshooting, and optimizing process performance.

4.3.Field Communicator

The HART communicator is ideal for monitoring or calibrating multiple instruments or for monitoring instruments in hazardous areas. The HART communicator does not require physical contact with the instrument, so it can be used in places where physical access is limited or hazardous. It also provides the ability to monitor or calibrate multiple instruments, which can be especially helpful in industrial or hazardous environments.

5. Which variables are offered by Rheonics for the HART protocol?

For HART communication, Rheonics provides the following variables (PV, SV, TV, and QV) over Channel 1 analog output 4-20mA.

It is possible to configure the variables to output other measurements including derived values like ° API, ASTM compensated density, temperature-compensated viscosity, etc. You can advise your sales contact to pre-configure or work with the support team to configure in the field. 

6. References:

Rockwell 1756 HART card[1]

Series C I/O Modules | Honeywell [2]

HART Communicator YHC5150X [3]

AMS Trex Device Communicator | Emerson US [4]

Disclaimer

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