In this support article, we will guide you through the process of configuring your HART Server to communicate using your new MUX. By following these step-by-step instructions, you'll be able to ensure proper functionality and optimize the performance of your device.

Confirming Device Type

To begin, you need the HART device type code for your new MUX. It will be 4 hexadecimal characters that are unique to the manufacturer of your device. In the remainder of this article, we will use type 40EF as an example. Note that this is not the device's model number. Here are some ways to determine the device type:

Look in the the user guide for the device or contact the manufacturer.

If you're HART network is up with the new MUX attached and you have HART Server running on the network, then use HART Server to browse to the device and check its properties. You will find the device type there.

Send a command 0 to the device to obtain its identity information, which includes the device type.

Accessing hartopc.ini File

The next step is to locate and open the hartopc.ini file. This file contains the necessary entries to configure your device correctly. Follow the instructions below to find and open the file:

Navigate to the directory where your hartopc.ini file is located. Typically, it is here: 

C:\Program Files (x86)\HART Server

Once you've located the file, open it using a text editor of your choice. Ensure that you have the necessary permissions to modify the file if required.

Verifying Network Types

Within the hartopc.ini file, you will find a section dedicated to network types. Typically this section does not change.

; Network Types



Ensure that the DLL entry points to the correct DLL file required for network communication. In this case, it should be set to netrs485.dll. The MaxAddress specifies the maximum address value, and MUX List should be set to MuxesForRS485.

MUX Lists for Network Types

Now, let's check the MUX Lists section in the hartopc.ini file. It should look like this:

; Mux Lists for Network Types


The [MuxesForRS485] section contain the device types organized by the network protocol. Make sure there is an entry in this list for your device type. If there is not one then add it by following the same pattern. Ensure that the entry is present and does not contain any typos or extra spaces.

MUX Types Configuration

The final step is to configure the MUX Types section. Locate the following section within the hartopc.ini file:

Often, the MUX is one of the following types: MTL, STAHL or HARTPORT. There is a standard DLL driver for each of those types.  Make sure there is an entry here for your device. If there is not, create one using this section as a pattern.

; Mux Types

Here, [40ef] denotes the device type we are configuring. The DLL entry specifies the DLL file required for proper device functionality. This DLL must match your MUX type or it will fail to operate correctly. The CHANNELS entry defines the number of channels supported by the device. Make sure to adjust the channel range according to your specific requirements.

Congratulations, you have successfully configured your mux device type 40ef. By following the steps outlined in this support article, you can ensure the optimal performance and functionality of your device. If you encounter any issues or need further assistance, don't hesitate to reach out to our support team.