Connect Via Modbus Part 3 – Creating a Program

Connect Via Modbus Part 3 – Creating a Program

By Anthony Dinh – Support Engineer

This Tech Tip is a follow on from parts 1 and 2 of previous titles ‘Connect Via Modbus with Red Lion and ABB’, and ‘Connect via Modbus – Part 2’.

We will be looking at creating a sample program to extract information from your ABB drive to your Red Lion device, that will include looking at the actual value references from your main drive such as frequency, motor speed, torque and current.


Creating data tags

Let’s start by creating four different data tags to link frequency, motor speed, motor torque and motor current of your drive from your HMI. Continuing from the program created in our first part, select the drop-down arrow from your navigation pane, and choose ‘New’, selecting Numeric tag. We are going to create four of the same numeric tags and rename them to the following:

- Read_freq                                  
- Read_speed                               
- Read_motor_tq                        
- Read_motor_current   

Change the source of the tags from ‘Internal’ to ‘ACQ580 ‘and select holding registers. Refer back to ‘Connect Via Modbus with Red Lion and ABB’ if you are having issues. Once the source has been changed to our ACQ580 device, change the data source access to ‘Read Only’. It should look like the images below.

Notice at the source, the holding registers for all four data tags are 400001. We are going to assign the appropriate holding register individually in reference to the values we would like to see from our drive. Navigate to ‘Pick…’

- Read_freq                                   400106               (Output Frequency)
- Read_speed                                400102               (Motor Speed)
- Read_motor_tq                         400110               (Motor Torque)
- Read_motor_current                 400107               (Motor Current)

Note: The last four digits for each holding register represents the parameter settings of the ACQ580 drive, these can be found in parameter listing – 01 Actual Values

01.06 – Output Frequency
01.02 – Motor Speed estimated 
01.10 – Motor Torque 
01.07 – Motor Current



Handy Tip: For your numeric tags you may need to turn on scaling, as the values may differ to what you may see later. The values can be scaled as shown above to the desired value, make sure you’re able to determine the minimum and maximum value before you set your scale.

To format your units for your values, click on your desired data tag located at the ‘Format’ tab. See below for ‘Format Units’ and enter your desire unit (e.g Hz, RPM, A, %).

You could also change the Label of your data tag and provide something more readable. This can be found in Format > Data Labels > Label.

We have created four ‘read only’ data tags to read values such as the frequency, motor speed, motor torque and motor current which was mapped to the appropriate holding register. Now we are going to create another tag to set and control the frequency of the drive. Very similar as before, we will create another ‘Numeric tag’ however this should be changed to as a ‘Read and Write’ and with the following holding register below, this would be another reference to the output frequency of the drive.

- Frequency                      400002


Creating your Display Page
Continuing from Tech Tip ‘Connect Via Modbus with Red Lion and ABB’, you would had previously created a Start and Stop button. To finalise the design of our user interface of our HMI, navigate to your resource pane to your right from display pages, and drag and drop the data tags we had created before onto the screen and it should look something similar to the below highlighted in yellow:



This is only a sample of what you can do, however you could add more functions and designs to your liking. In my example above, I’ve added warnings and alarms in case a fault occurs in the drive and a trend view in association to the data tags we’ve created.

This is available here if you would like to see how I did this. Good luck and thanks for following.

For more information call 1800 557 705 or email [email protected]


Reference material

FENA-01/11/-21 User manual

ACQ580 Firmware manual